Variable Stars in Young Open Cluster NGC 2244
MMon. Not. R. Astron. Soc. , 1– ?? (2018) Printed 30 May 2019 (MN L A TEX style file v2.2)
Variable Stars in Young Open Cluster NGC 2244
G. Michalska (cid:63) Instytut Astronomiczny, Uniwersytet Wrocławski, Kopernika 11, 51-622 Wrocław, Poland
Accepted ... Received ...; in original form ...
ABSTRACT
We present results of a
U BV I C variability survey in the young open cluster NGC 2244.In total, we found 245 variable stars. Most of them, 211 stars, are variables withirregular variations. Furthermore, 23 periodic variables were found. We also detectedfour candidates for δ Scuti stars and 7 eclipsing binaries.Based on the mid-infrared
Spitzer and WISE photometry and near infrared
JHK S r (cid:48) i (cid:48) H α IPHAS photom-etry and
JHK
UKIDSS photometry, were used for identification of pre-main sequencestars among irregular and periodic variables. In this way, 97 CTTS candidates (96 ir-regular and one periodic variable), 68 WTTS candidates (54 irregular and 14 periodicvariables) and 6 Herbig Ae/Be stars were found.For 223 variable stars we calculated membership probability based on proper mo-tions from Gaia DR2 catalogue. Majority of them, 143 stars, are cluster members withprobability greater than 70 percent. For only 36 variable stars the membership proba-bility is smaller than 20 percent.
Key words: open clusters and associations: individual: NGC 2244 – photometric –stars: pre-main sequence, circumstellar matter – infrared: stars – stars: variables: TTauri, Herbig Ae/Be, δ Scuti stars, eclipsing binaries.
Stars in open clusters form in approximately the same chem-ical environment and have nearly the same age and distance.Multiwavelength photometry of young stellar clusters allowsstudying stars at the pre-main sequence (PMS) stage of evo-lution. The photometric variations in these stars are believedto originate from several mechanisms like rotation of a spot-ted star or obscuration by circumstellar matter (see Herbstet al. 1994, and references therein). PMS stars are usually di-vided into two main groups: low mass ( < (cid:12) ) T Tauristars (TTSs) and more massive (1.5 – 15 M (cid:12) ) Herbig Ae/Be(HAeBe) stars (Artemenko et al. 2010). Depending on thestrength of the emission in the H α line, the TTSs are di-vided into weak line TTSs (WTTSs; with equivalent widths(EW), smaller than 10 ˚A) and classical TTSs (CTTSs; withEW >
10 ˚A). Both WTTSs and CTTSs show brightness varia-tions in X-ray, ultraviolet, optical and infrared domains.Photometric variability of CTTSs is irregular. It may beattributed to unsteady accretion from the circumstellar diskas well as rotation of the surface hot and dark spots. The am- (cid:63)
E-mail: [email protected] plitudes range from few hundredths to several magnitudes in V band (Herbst et al. 2000). The light variations of WTTSsare periodic and related to the rotation of large dark spots onstellar surface. Typical periods of such changes range between0.5 and 18 days with amplitudes between 0.03 and 0.3 magin V band (Semkov 2011).The HAeBe stars, defined by Herbig (1960), have spectraltypes earlier than F5 and are characterized by broad emissionlines and infrared excess due to a circumstellar disk. They areoften located in obscured regions, in the vicinity of bright neb-ulae. Their light variability is irregular, connected with accre-tion processes and dust clumps in the surrounding disk. Lightcurves of many HAeBe stars with spectral types later than A0and some TTS show 1 – 3 mag deep algol-like minima lastingseveral days to weeks. This class of variable is called UX Orio-nis stars (UXors), after the prototype star UX Ori (Herbst et al.1994).The other interesting group of variable PMS stars arelow-mass FU Orionis stars (Herbig 1977) – FUors. The char-acteristic feature of these objects is an increase in brightnessby about 3 – 6 mag, lasting several months, followed by a slowdecay over several years. The brightening is caused by a sud-den change in the accretion rate from about 10 − M (cid:12) yr − (typical for TTSs) to 10 − M (cid:12) yr − . Their spectral types c (cid:13) a r X i v : . [ a s t r o - ph . S R ] M a y G. Michalska change from typical for TTS to F or K-type supergiant. Thethird group of irregularly variable PMS stars are EXors, afterthe prototype, EX Lupi (Herbig 1989). These stars repeatedlyundergo increase in brightness by about 1 – 4 mag, and, aftera few weeks or months, fade back to their original brightness.The observations (in particular, of stars in very youngopen clusters) show that some PMS stars pulsate or at leastsome candidates for PMS pulsating stars can be indicated. Inrecent years, the number of known PMS pulsating stars in-creased largely. The most common are PMS δ Sct-type (Zwintz2008; D´ıaz-Fraile et al. 2014) and γ Dor-type stars (Zwintzet al. 2013). A hybrid δ Sct/ γ Dor candidate was even found(Ripepi et al. 2011). By now, no confirmed SPB or β Cephei-type PMS star is known, however, although two suspectedPMS SPB stars were discovered from the optical photometryobtained by MOST satellite in the region of NGC 2244 (Gru-ber et al. 2012).In this paper, we present the results of the search for vari-able stars in the very young open cluster NGC 2244. The paperis organized as follows. First, we briefly introduce the cluster,our photometric observations, reduction process and transfor-mation to the standard system (Sect. 2). Variable stars foundin the field we observed and their membership probabilityare presented in Sect. 3 and Sect. 4, respectively. The identi-fication of Young Stellar Objects based on
Spitzer and 2MASSphotometry is described in Sect. 5. The classification of PMSvariables is discussed in Sect. 6. The results are summarizedin Sect. 7.
U BV I C PHOTOMETRY2.1 The cluster
The very young open cluster NGC 2244 is associated with thefamous Rosette Nebula and located in the Perseus Arm of theGalaxy. Its age, based on isochrone fitting, was estimated for2 – 4 Myr, the distance for 1.4 – 1.7 kpc, and the reddening, interms of the colour excess E ( B − V ) , for 0.47 mag (Ogura &Ishida 1981; Hensberge et al. 2000; Park & Sung 2002). Thecluster is embedded in H II region and is rich in O and B-typestars. Its photometric UBV I C and H α study was performedby Park & Sung (2002). They classified about 30 O and B-type cluster members. They also discovered 21 PMS stars withH α in emission (four of them are massive HAeBe stars) andsix PMS candidates with detectable X-ray emission. A largepopulation of PMS stars in NGC 2244 was also reported byBonatto & Bica (2009) and Bergh¨ofer & Christian (2002).The cluster contains O-type β Cephei type star (Briquetet al. 2011), double-lined eclipsing binary V578 Mon (Hens-berge et al. 2000) and several other spectroscopic binaries.It also contains one known Ap star, NGC 2244-334 (Bagnuloet al. 2004), having strong magnetic field. This star, however,was outside the field we observed.
The photometric observations of NGC 2244 were carried outwith the Yale SMARTS 1-m telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile. The telescope wasequipped with Y4KCam CCD camera covering about 20 (cid:48) × (cid:48) area in the sky. Between December 24, 2008 and January 8, 2009, we collected about 2000 frames in V filter, 170 framesin I C filter, 150 in B filter, and 70 in U filter. The exposuretimes ranged from 15 to 200 s, depending on the filter, seeingand sky transparency. All frames were calibrated with the useof Phil Massey scripts designed to Y4KCam. Then, the imageswere reduced with the DAOPHOT II package (Stetson 1987,Stetson 1992). Our photometry was transformed to the standard system.Since many observed stars show irregular variability, we de-cided to calculate mean instrumental magnitudes and coloursapplying 2 σ clipping. Then, these mean values were tied tothe UBV I C photometry of NGC 2244 published by Park &Sung (2002). The transformation was based on the photom-etry of about 400 stars common with these authors. The fol-lowing transformation equations were obtained: V − v = ( ± ) × ( v − i ) + ( ± ) , (1) V − I C = ( ± ) × ( v − i ) + ( ± ) , (2) B − V = ( ± ) × ( b − v ) + ( ± ) , (3) U − B = ( ± ) × ( u − b ) + ( ± ) , (4)where u , b , v and i denote the mean instrumental magnitudesfrom our photometry, while U , B , V , and I C , the standardmagnitudes. The residual standard deviations for the trans-formation equations were equal to 0.030, 0.016, 0.014 and0.034 mag for Eq. (1), (2), (3), and (4), respectively.From the above equations, we computed V magnitudesand the ( V − I C ) colour indices for 4058 stars, and the ( U − B ) and ( B − V ) colour indices for 989 and 1347 stars, respec-tively. Standard photometry of the variable stars is given inTable A1 in Appendix. The equatorial coordinates shown inthis Table A1, were determined by means of an astrometrictransformation of mean stellar positions derived from imageswith the use of IRAF ccmap/cctran tasks. As a reference cata-logue, we used the UCAC4 catalogue (Zacharias et al. 2013). U BV I C photometry The magnitudes and colours derived in Sect. 2.3 are shownin the V vs. ( B − V ) and V vs. ( V − I C ) colour–magnitudediagrams (Fig. 1), and in the ( U − B ) vs. ( B − V ) and ( U − B ) vs. ( V − I C ) colour–colour diagrams (Fig. 2). The distance of1.7 kpc, i.e. ( m − M ) = 11 . mag, the mean colour excesses E ( B − V ) = 0 . mag, E ( V − I ) = 0 . mag and the totalabsorption in V , A V = 1 . mag, were adopted from Park &Sung (2002). As can be seen in these figures, many stars arein their PMS phase of evolution and plenty of them are vari-able (coloured symbols). Their position spread between 0.5and 10 Myr in the colour–magnitude diagrams may be causedby differential reddening towards NGC 2244, mentioned byBergh¨ofer & Christian (2002), or the stars were formed not atthe same time. The variable reddening towards the early-typestars in NGC 2244 was reported by Massey et al. (1995) who The full version of Table A1 is available in electronic form from theCDS. c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 V [ m ag ] B - V [mag] C [mag] Figure 1.
Variable stars in V vs. ( B − V ) ( left ) and V vs. ( V − I C ) ( right ) colour-magnitude diagrams for the observed field. The symbols indicatevariable stars found in this paper: pulsating stars(red squares), eclipsing stars (pink diamonds), other periodic variables (green) and remainingvariables (blue). Some variables discussed in text are labeled. The ZAMS relation (thick line) was taken from Pecaut & Mamajek (2013). Theisochrones (dotted lines) for 0.1, 0.5, 1, 2, 6, 10, and 100 Myr were taken from Bressan et al. (2012). -1-0.5 0 0.5 1 1.5 2 0 0.5 1 1.5 2 U - B [ m ag ] B - V [mag] -1-0.5 0 0.5 1 1.5 2 0 0.5 1 1.5 2V - I C [mag] Figure 2.
Variable stars in ( U − B ) vs. ( B − V ) ( left ) and ( U − B ) vs. ( V − I C ) ( right ) colour-colour diagrams for the observed field. The symbolsare the same as in Fig. 1. The dashed lines represent intrinsic relations for dwarfs (black) and for giants (blue) taken from Caldwell et al. (1993).The solid lines are the relations shifted adopting E ( B − V ) = 0 . mag, E ( V − I C ) = 0 . mag and E ( U − B ) /E ( B − V ) = 0 . (Massey et al.1995).c (cid:13) , 1–, 1–
Variable stars in ( U − B ) vs. ( B − V ) ( left ) and ( U − B ) vs. ( V − I C ) ( right ) colour-colour diagrams for the observed field. The symbolsare the same as in Fig. 1. The dashed lines represent intrinsic relations for dwarfs (black) and for giants (blue) taken from Caldwell et al. (1993).The solid lines are the relations shifted adopting E ( B − V ) = 0 . mag, E ( V − I C ) = 0 . mag and E ( U − B ) /E ( B − V ) = 0 . (Massey et al.1995).c (cid:13) , 1–, 1– ?? G. Michalska : : : : : : : : D E C RA Figure 3.
Schematic map of the observed field. Variable stars aremarked with colours: pulsating stars (red squares), eclipsing stars(pink diamonds), other periodic variables (green circles) and remain-ing variables (blue circles). Some variables discussed in text are la-beled. obtained minimum and maximum values of E ( B − V ) equalto 0.38 and 0.85, respectively. The estimation of masses andages for PMS stars depends a lot on the adopted theoreticalmodels of evolution (Bell et al. 2013).As can be seen in Fig. 1, some stars lie close to or on theleft side of ZAMS line. They are not cluster members. Amongthem, there are four eclipsing binaries, two δ Scuti candidatesand several other variables. They are marked as ”nm” in thelast column in Table A1 in the Appendix.
The variability search was based mainly on the Fourier pe-riodograms, calculated up to 80 d − . In addition, the lightcurves, periodograms and phased light curves for all starswere inspected by eye. Out of over 4000 stars in the observedfield, 245 turned out to be variable. The brightest stars in ourobservations are strongly saturated. Since the Y4KCam is readout through four amplifiers, the saturation in one quadrantcauses significant crosstalk, saturated in the remaining quad-rants. This could have affected photometry of some stars.In this section we present the main properties of the vari-able stars which we divided into four groups: pulsating stars,binary stars, other periodic variables and the remaining vari-ables. Their location in schematic map of observed field isshown in Fig. 3. Some examples of variable stars in the clus-ter field were already announced by Michalska (2014). There is one O-type star in NGC 2244, HD 46202 (Massey,Johnson & Degioia-Eastwood 1995), which was reported tobe β Cephei type star (Briquet et al. 2011). Based on CoRoTdata, the authors found eleven oscillations with frequencies % o f da t a s e t s S/N 4.64
Figure 4.
The percentage of correct frequency detections for timeseries of observed pulsating stars vs. signal to noise. Dashed linerepresents the confidence level equal to 80% which corresponds toS/N=4.65. A m p li t ude [ mm ag ] f f x f f -1 ] Figure 5.
Fourier frequency spectrum of the V -filter data of star 5:original data (top), after removing f and f x (middle) and after re-moving f , f x , f , f and f (bottom). between 0.5 and 5 d − and amplitudes of about 0.1 mmagor less. We observed this star, but apparently the amplitudeswere below our detection threshold. We did not find any β Cephei or SPB stars in our photometry, but it cannot be ex-cluded that some of early type stars, saturated in our data,pulsate. Two SPB stars discovered by Gruber et al. (2012)were outside our field of view.Out of 245 variables detected in the observed field, fourappear to be δ Scuti stars. The parameters of the sinusoidalterms (frequencies, f i , amplitudes, A i , and phases, φ i ) forthese stars, were derived by fitting the formula (cid:104) m (cid:105) + n (cid:88) i =1 A i sin( πf i ( t − T ) + φ i ) (5)to the differential magnitudes. In Eq. (5) (cid:104) m (cid:105) is the meandifferential magnitude, n , the number of fitted terms, t , thetime elapsed from the initial epoch T = HJD 2455000. Theparameters of the fit are listed in Table 1. Instead of φ i , weprovide the time of maximum light, T max .In order to evaluate signal-to-noise, S/N, corresponding c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Table 1.
Parameters of the sine-curve fits to the B , V and I C differential magnitudes of the pulsating stars detected in the observed field. Thenumbers in parentheses denote the r.m.s. errors of the preceding quantities with the leading zeroes omitted. The σ res is the residual standarddeviation, N obs stands for the number of observations, S/N is the signal-to-noise ratio.star f i Filter N obs A i T max − T S/N σ res
Spectal Other[d − ] [mmag] [d] [mmag] type name5 31.3106(12) f B
130 5.7(5) 5195.6258(04) 8.8 3.7 A0/A2 W69 V f x V f V f V f V f V f V f V f V f V f V f V f V f V f V f V f x V f V f V f V f V B
148 43.6(67) 5196.262(3) 5.4 57.0 V I C
167 15.9(25) 5196.959(2) 5.3 21.792 20.147(4) V to the the probability of finding real signal equal to 80%,we used the method described by Baran et al. (2015). First,1000 files with Gaussian noise for a given standard devi-ation were generated, and the average noise in the peri-odogram was calculated. Then, a sinusoidal signal in the formof A sin(2 πft + φ ) was added. In this formula, t represents thetime of observation, φ is the phase taken as random value inthe range [0,2 π ], and A is amplitude of the signal coveredthe range of signal-to-noise (S/N) between 1 and 8, with thestep of 0.05 mmag. For each amplitude, we generated 1000time-series datasets for which Fourier periodograms were cal-culated and the number of files with peak at the added fre-quency was counted. As can be seen in Fig. 4, the detec-tion threshold with the 80% confidence level correspondingto S/N=4.64. For this reason, in Table 1 we show only thefrequencies with S/N (cid:62) δ Scuti candidates is star 5 (GSC 00154-01743).The Fourier frequency spectrum of its V -filter data (Fig. 5)reveals frequency f = − . After prewhitening orig-inal data with this frequency, we found the frequency f x = − (likely instrumental) and three other significantterms with frequencies f = − , f = − and f = − , typical for δ Scuti stars. The spec-
20 30 A m p li t ude [ mm ag ] f f f f f f f f f
10 f x f f f f f -1 ] Figure 6.
Fourier frequency spectrum of the V -filter data of the δ Scuti candidate, star 18, at four steps of prewhitening.c (cid:13) , 1–, 1–
Fourier frequency spectrum of the V -filter data of the δ Scuti candidate, star 18, at four steps of prewhitening.c (cid:13) , 1–, 1– ?? G. Michalska A m p li t ude [ mm ag ] f = 11.5336 d -1 -1 ] Figure 7.
Fourier frequency spectrum of the V -filter data of the δ Scuti candidate, star 75: original data (top), after removing f =11 . d − . A m p li t ude [ mm ag ] f = 20.147 d -1 -1 ] Figure 8.
Fourier frequency spectrum of the V -filter data of the δ Scuti candidate, star 92: original data (top), after removing f =20 . d − . tral type in WEBDA database, reported by Kuznetsov (1986)is A0. In Simbad database the spectral type of star 5 is A2.The fitted spectral type, derived from synthetic photometry byPickles & Depagne (2010), is B8V, however, it appears to betoo early for δ Scuti star. The position in ( U − B ) vs. ( V − I C ) colour-colour diagram (Fig. 2) indicates that this star is nota member of NGC 2244. The probability of its membershipranges between 0.16 (Marschall et al. 1982) and 0.88 (Chenet al. 2007). Based on Gaia proper motions we obtained theprobability equal to 0.27 (Sect. 4).For three other δ Scuti candidates the spectral types arenot available. Using prewhitening method with the subse-quent strongest modes we found fifteen frequencies in Fourierperiodogram of star 18 (Fig. 6). The periods, the multiperiod-icity and the shape of light curve are typical for a δ Scuti star.In each of two other stars, star 75 and 92, we found only onefrequency of variability, characteristic for δ Scuti-type vari-ables: f = − (Fig. 7) and f = − (Fig. 8),respectively.Assuming that all four δ Scuti candidates are clustermembers, we calculated absolute magnitudes, M V , and ( B − V ) adopting A V = 1 . mag, E ( B − V ) = 0 . mag andthe distance modulus equal to 11.1 mag found by Park &Sung (2002). These values for two δ Scuti candidates, star 5and 18, are plotted in colour-magnitude diagram (Fig. 9) to-gether with 18 pulsating PMS stars and candidates from clus-ters (blue dots) and two pulsating PMS field stars with best -1 0 1 2 3-0.1 0 0.1 0.2 0.3 0.4 0.5 M V (B - V) Figure 9.
Position of two δ Scuti candidates, star 5 and 18 (red dots)in HR diagram. Additionally, 18 pulsating PMS stars and candidatesfrom clusters (blue dots) and two pulsating PMS field stars (greendots) taken from Zwintz (2008) are plotted. The ZAMS (solid line),the borders of the classical δ Scuti instability strip (dotted lines) andclassical δ Scuti stars (grey dots) were transformed from the data ofRodr´ıguez & Breger (2001). The dashed line represents isochronesfor 6 and 10 Myr taken from Bressan et al. (2012). parallaxes (green dots), taken from Table 3 and 4 of Zwintz(2008), respectively. The author notified that PMS pulsatorsoccupy the same instability region in H-R diagram as classi-cal δ Scuti stars, marked with grey dots in Fig. 9. We derivedtheir ( B − V ) from ( b − y ) colours published by Rodr´ıguez &Breger (2001) using transformation given by Caldwell et al.(1993). The instability strip (dotted line) and ZAMS (solidline) were also transformed from the data of Rodr´ıguez &Breger (2001). As can be seen in this diagram, star 18 issituated inside the instability strip. Its position is quite closeto ZAMS and it appears to be older than cluster members.The membership probability determined in Sect. 4 is equalto 62.2%. Furthermore, its position in V vs. ( B − V ) and V vs. ( V − I C ) colour-magnitude diagrams (see Fig. 1) indicatesthis star is rather old.Since the ( B − V ) colours of star 75 and star 92 aregreater than 0.5 and M V is close to 5 mag, we did not showthem in Fig. 9. If these stars are of δ Scuti-type, they are fieldstars, located beyond NGC 2244. Their membership probabil-ity determined in Sect. 4 is equal to 1.1% and 0% for star 75and 92, respectively. The star 5 have ( B − V ) = − . andit is outside the instability strip borders. This indicates it islikely a foreground star. We identified seven stars (WEBDA numbers: 59, 80, 119, 128,133, 194, and 201), previously known as single lined spectro-scopic binaries (Huang & Gies 2006). All they are not variablein our data. In the observing field there are also two double-lined spectroscopic stars, HD 46149 (Mahy et al. 2009) andHD 46150 (Chini et al. 2012). The primary components ofboth systems are O-type stars. Unfortunately, they are satu-rated in our photometry.NGC 2244 contains a close visual pair, HD 46180 ( V A = (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 -0.7-0.6-0.5-0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 0 0.2 0.4 0.6 0.8 1 1.2 D i ff e r en t i a l m agn i t ude PhaseBVI C ASAS1 = V578 Mon
Figure 10.
Phase diagrams of the V -filter ASAS observations and our BV I C observations of eclipsing system V578 Mon. Offsets were ap-plied to separate light curves in different bands. Table 2.
Parameters of eclipsing binary stars found in the observedfield. The depths of eclipses are given for the V -filter observations.The numbers in parentheses denote the r.m.s. errors of the precedingquantities with the leading zeroes omitted.Star Period T min I [d] Eclipse depth[d] HJD-2450000 I [mag] II [mag]1 2.411(1) 5203.7289(33) 0.11 0.081 (cid:63) (cid:63) for V -filter ASAS data . , V B = 10 . , ρ = 5 . arcsec and θ = 82 ◦ ; Masonet al. 2001). Based on DDO (David Dunlap Observatory) spec-troscopy obtained for MOST variables, Pribulla et al. (2009)discovered that HD 46180 is a quadruple system composedof two binary stars. One pair is an eclipsing system withthe orbital period of about 3.09 d and amplitude 0.016 mag(Pribulla et al. 2010). Unfortunately, HD 46180 and the otherstar are not resolved in our data, and they are saturated. Con-sequently we are not able to detect any eclipses.There is also a well-known eclipsing system V578 Mon inthe observed field (star 1 in our list of variable stars). Accord-ing to Hensberge, Pavlovski & Verschueren (2000), this binaryhas an orbital period equal to 2.40848 d, and consists of twomassive ( M = 14 . ± . M (cid:12) and M = 10 . ± . M (cid:12) ) early B-type stars (B1V+B2V). The age of the systemand the distance derived by these authors are equal to . ± . Myr and . ± . kpc, respectively. The eccentricity of about0.077 and apsidal motion equal to 0.071 deg cycle − (ap-sidal period equal to 33.48 yr) were determined by Garciaet al. (2011). The absolute dimensions of V578 Mon wererecently determined by Garcia et al. (2014). They found theradii R = 5 . ± . R (cid:12) and R = 4 . ± . R (cid:12) , and effec-tive temperatures T = 30000 ± K and T = 25750 ± K. The
BV I C phased diagram of V578 Mon is shown in Fig. 10. Since this bright system ( V = 8 . mag) is partiallysaturated in our photometry, we were not able to determinethe period accurately. For this purpose, we used ASAS data(Pojma´nski 2003) and we got P = 2 . d which is con-sistent with the period of Hensberge, Pavlovski & Verschueren(2000).V578 Mon was also observed by MOST. Based on thisphotometry, Pribulla et al. (2010) found the orbital period P = 2 . d. Adopting mass ratio q = 0 . from spec-troscopy, they obtained inclination i = 73 . ◦ , the relative radii r = 0 . and r = 0 . , the eccentricity e = 0 . and sur-prisingly low for early B-type stars the effective temperatures, T = 16980 K and T = 13310 K.The other eclipsing system found in our data is V552Mon (star 54 in our list of variable stars). In General Cata-log of Variable Stars (GCVS) its type of variability has beenassigned as IN:, i.e. probable irregular eruptive star (Samuset al. 2009). There is no information about variability andspectral type of five other eclipsing binaries (19, 48, 72, 170,205). The periods, the times of minimum, and the eclipsedepths for each eclipsing binary are given in Table 2. Thephase diagrams are shown in Fig. 11.The positions of systems 19 and 48 in the V − ( V − I C ) colour-magnitude diagram (Fig. 1) indicate that they can becluster members. Four other binaries (54, 72, 170 and 205)are close to ZAMS in this diagram, so they are probably non-members. It cannot be excluded, however, that the changes intheir light curves some of them are caused by cool spots. Thistype of variability is described in Sect. 3.3.We found many variables with evident eclipse in theirlight curve, showing also another type of variability. For thisreason we describe them in Sect. 3.4, together with other ir-regular variables. In addition to pulsating stars (Sect. 3.1) and eclipsing systems(Sect. 3.2) we found a group of 23 other periodically variablestars. Their periods, times of the maximum and amplitudesare listed in Table 3. The phase diagrams of these stars areavailable online in electronic version. In colour-magnitude(Fig. 1) and colour-colour (Fig. 2) diagrams these stars aremarked as green dots. Almost all these stars appear to becluster members. The shape of light curves and the positionin colour-magnitude diagram indicate that most of these pe-riodic stars may be WTTS stars.The WTTSs do not have active accretion disks and thechanges in their light curves are mainly caused by cool spots(Bouvier et al. 1993, Herbst et al. 1994). As we mentionedin the Introduction, the typical periods of such variability are0.5–18 d (Semkov 2011). Our observations do not allow toderive the longest periods from this range, so that in Table 3we list stars only with periods shorter than half of the observ-ing time. We did not find any star with period shorter thanone day, although, in other clusters, e.g. NGC 2282, there areup to 50% of such stars (Dutta et al. 2018).The faster rotation of the stars with decreasing masses isclearly seen in old open clusters (Henderson & Stassun 2012).Some authors, however, show correlation between periodsand masses of stars in young open cluster. Lata et al. (2012),who analyzed PMS variable stars of NGC 7380, NGC 1893 andBe59, show that stars with masses greater than 2 M (cid:12) rotate c (cid:13) , 1– ?? G. Michalska -0.2-0.1 0 0.1 0.2 0.3
BVI C D i ff e r en t i a l m agn i t ude -0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 0.5 BVI C -1.5-1-0.5 0 0.5 1 1.5 UVI C B54 = V552 Mon -0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 0 0.2 0.4 0.6 0.8 1 1.2
BVI C -0.4-0.3-0.2-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0 0.2 0.4 0.6 0.8 1 1.2 VI C -0.6-0.4-0.2 0 0.2 0.4 0.6 0.8 1 1.2 0 0.2 0.4 0.6 0.8 1 1.2 VI C Figure 11.
Phase diagrams of six eclipsing systems (star 19, 48, 54, 72, 170 and 205). Offsets were applied to separate light curves in differentbands.
Table 3.
Parameters of 23 periodic variable stars found in theobserved field determined from the V -filter observations ( T =2450000 ). The numbers in parentheses denote the r.m.s. errors ofthe preceding quantities with the leading zeroes omitted.Star Period T max − T Amplitude[d] [d] [mmag]11 1.39484(45) 5198.3285(18) 25.0(02)20 2.3533(10) 5198.2599(24) 63.5(04)27 2.9650(30) 5197.988(64) 37.8(61)43 2.9207(21) 5197.1121(78) 170.3(24)53 5.715(16) 5196.617(11) 69.7(07)57 1.73898(41) 5197.36557(91) 361.9(10)59 1.7338(11) 5199.1084(41) 58.4(09)62 3.8134(68) 5196.9136(65) 92.5(10)79 2.2971(17) 5198.6714(39) 100.5(12)85 4.1615(99) 5200.3439(92) 82.2(12)90 2.72813(65) 5199.5292(16) 388.3(14)93 1.58577(91) 5198.5312(26) 132.9(13)95 1.5282(13) 5198.6391(34) 89.3(12)100 1.8069(14) 5198.3071(37) 111.1(14)103 1.6836(16) 5198.3854(59) 58.96(13)105 5.212(18) 5196.195(13) 86.4(15)113 1.10223(34) 5198.5434(21) 174.3(19)135 1.07587(73) 5199.3193(33) 95.9(18)137 4.4913(51) 5199.7514(99) 231.0(34)151 2.3023(24) 5196.3062(51) 187.4(24)166 5.142(17) 5198.089(13) 173.1(27)182 4.9095(86) 5196.773(14) 257.3(46)192 6.880(23) 5196.916(20) 176.4(34) faster. The opposite dependence was found by Lamm et al.(2005) who studied the period distribution of PMS variablesin Orion Nebula Cluster and in NGC 2264. They show that lowmass stars rotate faster, on average, then high mass stars. In
13 14 15 16 17 18 19 20 0.5 1 1.5 2 2.5 3 3.51.5 M ⊙ ⊙ ⊙ ⊙ V [ m ag ] V - I C [mag] Figure 12.
Position of the periodic variables in the colour-magnitudediagram. The ZAMS relation for Z=0.02 (thick line) was taken fromPecaut & Mamajek (2013). The symbols represent four ranges of pe-riods: 1–2 days (blue dots), 2–3 days (green squares), 3–5 days (redtriangles) and more than 5 days (magenta diamonds). The isochrones(dotted lines) for 0.1, 0.5, 1, 2, 6, 10, and 100 Myr and mass tracks(dashed lines) were taken from Bressan et al. (2012). We adoptedhere mean values of E ( V − I C ) = 0 . mag, A V = 1 . mag and ( m − M V ) = 11 . mag. order to verify if there is any relation in our sample of periodicvariables, we checked their position in the colour-magnitudediagram shown in Fig. 12. The coloured symbols in this dia-gram represent four ranges of periods: 1–2 days (blue dots),2–3 days (green squares), 3–5 days (red triangles) and morethan 5 days (magenta diamonds). The isochrones and mass c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 tracks were taken form Bressan et al. (2012). As can be seenin this figure, the stars with different periods are distributedin a wide range of masses. However, we note that in our sam-ple there are no stars with periods of less than 1 day and morethen 7 days. The remaining 211 variable stars are classified as irregular.Their light curves are available online in electronic version.As can be seen in these figures, the range of light variation ofsome stars is greater than 0.5 mag (e.g. stars 149, 186, 216,and 232). Some of them show an increase in the light similarto those observed in FUors (e.g. variable 34 and 131) or EXors(e.g. variable 83, 211) stars, but the time scale of variationsis much shorter.Almost all irregular variables lie between 0.1 and 6 Myrisochrones in the V vs. ( V − I C ) colour-magnitude diagram(Fig. 1), in the region of pre-main sequence stars. The vari-ability of these stars can be therefore caused by changesin the accretion disks and hot spots which is typical forCTTSs (Herbst et al. 1994, Kurosawa & Romanova 2013).The eclipses in the light curves which can be seen in someof them (82 and 149) indicate that these stars are obscuredby the dust clumps although they can be members of binaryor multiple systems.Five irregular variable (star 2, 3, 9, 50, and 67) havestrong H α emission (Park & Sung 2002). Three of them, star2 (spectral type B4 Ve), star 3 (B7 Ve) and star 9, are markedby these authors as HAeBe candidates. Strong emission in H α line of stars 2, 3 and 6 was notified by Li et al. (2002) whoclassified star 3 as Herbig Be and star 6 (spectral type F3 Ve)as HAeBe candidate.In addition to CTTSs and HAeBe, among irregular vari-ables, we can also find WTTS stars. Some more details aboutclassification of PMS variable stars can be found in Sect. 6.3. An important step in studying a cluster is the determination ofthe membership in its field. Some non-members can be iden-tified using the colour-magnitude diagram. The V − ( V − I C ) colour-magnitude diagram for the observed stars is shown inthe left panel of Fig. 13. As we mentioned in Sect. 2, the ageof NGC 2244 was estimated at 2 – 4 Myr so that we consid-ered stars below the 10 Myr isochrone (blue line in Fig. 13)as non-members.The other way of membership determination is the useof proper motions. A statistical method was proposed byVasilevskis et al. (1958) who used the distribution functionsof proper motions for cluster and field stars to derive mem-bership probability for individual stars. The method was mod-ified over the years (Sanders 1971, Zhao & He 1990). In thispaper, we applied the method used by Sariya et al. (2012)who defined the membership probability of the i th star as P µ ( i ) = n c . φ νc ( i ) n c . φ νc ( i ) + n f . φ νf ( i ) , (6) where n c and n f are the normalized numbers of stars for clus-ter and field ( n c + n f = 1 ) and φ νc and φ νf are the frequencydistribution functions for the cluster and field stars, definedas: φ νc = 12 π (cid:112) ( σ xc + (cid:15) xi )( σ yc + (cid:15) yi ) × exp (cid:26) − (cid:20) ( µ xi − µ xc ) σ xc + (cid:15) xi + ( µ yi − µ yc ) σ yc + (cid:15) yi (cid:21)(cid:27) (7)and Φ νf = 12 π (cid:112) (1 − γ ) (cid:112) ( σ xf + (cid:15) xi )( σ yf + (cid:15) yi ) × exp (cid:26) − − γ ) (cid:20) ( µ xi − µ xf ) σ xf + (cid:15) xi − γ ( µ xi − µ xf )( µ yi − µ yf ) (cid:112) ( σ xf + (cid:15) xi )( σ yf + (cid:15) yi ) + ( µ yi − µ yf ) σ yf + (cid:15) yi (cid:35)(cid:41) , (8)where µ xi and µ yi are the proper motions of the i th star( µ xi = µ α cos δ and µ yi = µ δ of the i th star) with errors (cid:15) xi and (cid:15) yi , respectively. The parameters µ xc and µ yc definethe cluster proper motion centre with dispersions σ xc and σ yc , while µ xf and µ yf are the field proper motion centrewith dispersions σ xf and σ yf , respectively. The correlationcoefficient γ was calculated by γ = ( µ xi − µ xf )( µ yi − µ yf ) σ xf σ yf , (9)In order to find the membership probability for each starwe observed, we used the proper motions from the Gaia DR2catalogue (Gaia Collaboration et al. 2016, Gaia Collaborationet al. 2018). For about 4000 stars in the observed field, wesearched for Gaia counterparts in the search radius of 1 (cid:48)(cid:48) . Us-ing the sample of about 50 stars with membership probabilitygreater than 70% from the catalogue of Park & Sung (2002),the mean proper motion of the cluster were calculated us-ing 3 σ clipping. We obtained µ α cos δ = − . mas yr − and µ δ = 0 . mas yr − with standard deviation σ µ α = 0 . and σ µ δ = 0 . , respectively. The proper motions from GaiaDR2 catalogue are shown in the right panel of Fig. 13. Aswe can see, most of our variable stars have proper motionsconcentrated around the calculated center (black cross). Weassumed that cluster stars are within an ellipse with semi-axisequal to σ µ α and σ µ δ . We find 426 stars within this area,for which V magnitudes and ( V − I C ) colours placed themabove 10 Myr isochrone in V − ( V − I C ) colour-magnitudediagram. For this sample we calculated mean proper motionof the cluster µ xc = − . and µ yc = 0 . mas yr − withdispersions σ xc = 0 . and σ yc = 0 . mas yr − . For the re-maining 3546 stars we calculated the mean proper motion offield stars µ xf = − . and µ yf = − . mas yr − with dis-persions σ xf = 3 . and σ yf = 4 . mas yr − . These valuesallow to calculate frequency distribution functions φ νc and φ νf ,and then the probability P µ ( i ) for each star. The probabilitiesfor variable stars are shown in Table A1. c (cid:13) , 1– ?? G. Michalska V =1.46m-M V =11.1E(V-I)=0.6 V [ m ag ] V - I C [mag] -6-4-2 0 2 4 -6 -4 -2 0 2 4 µ δ [ m a s / y r ] µ α cos δ [mas/yr] Figure 13.
Left : Colour-magnitude diagram for about 3600 stars in the observed field.
Right : Proper motions distribution for about 3600 stars inthe observed field. Green circles represent variable stars falling into the oval area around mean proper motion of NGC 2244 (black cross), redcircles – variable stars with V and ( V − I C ) below isochrone 10 Myr (blue line), black circles – other variable stars. Before we classify the PMS variable stars, described inSect. 3.3 and 3.4, first we deal with the classification ofyoung stellar objects (YSOs). The YSOs comprise both pro-tostars and PMS stars. The YSOs are frequently embedded intheir parental molecular clouds or have circumstellar disks.The presence of the embedding matter makes classificationbased on the infrared data quite obvious. In this paper, weuse 2MASS, Spitzer (IRAC and MIPS), and WISE infrared pho-tometry to identify which stars we detected in NGC 2244 areYSOs.Lada (1987) divided YSOs into three classes, I, II, and III.Class I sources are objects deeply embedded in the surround-ing cloud with emission dominated by the cold dust of theirenvelopes (protostars). They practically cannot be detected inthe visual domain. Class II sources having accretion disks areidentified with TTSs and are visible in the optical range al-though they have infrared excesses. Finally, Class III are post-T Tauri objects with no or little infrared excess. Their pho-tometric properties are similar to the normal main-sequencestars.Three other classes of YSOs were proposed in the liter-ature. Using observations in the submillimeter domain, An-dre et al. (1993) found extremely young object and proposeda fourth class of YSOs, Class 0. The Class 0 source cannotbe seen even in near- or mid-infrared. The fifth class, called“flat spectrum” (hereafter FS), was proposed by Greene et al.(1994) based on the slope of SED calculated between 2.2 and10 µ m, defined as α = d log( λF λ ) /d log λ , which is between − α > − < α < − α < − µ m, Lada et al.(2006) found that objects with thick disks have spectral index α > − − < α < − α < − Spitzer
IRAC and MIPS photometry, and 2MASS photometryfor selection Class I, Class II and transition disk objects.
Spitzer and 2MASS photometry
The
Spitzer data were taken from catalogue published by Ba-log et al. (2007). We found 674 counterparts in this catalogueputting an offset of 2 (cid:48)(cid:48) between our and
Spitzer positions. Al-most all of them have photometric uncertainties σ < . mag.All of them have photometry in all four IRAC bands ([3.6],[4.5], [5.8] and [8.0] µ m) but only 167 stars have MIPS pho-tometry ([24] µ m).At the beginning, according to the criteria of Gutermuthet al. (2009) and Megeath et al. (2009), we identify extra-galactic sources that may be misclassified as YSOs. They aremarked with white squares in Fig. 14 −
16. The other sym-bols shown in Fig. 14 −
16 denote our final classification of theYSOs, described in Sect. 5. We found only one object that sat-isfy colour and brightness criteria (marked with dashed linein Fig. 14a) for active galactic nuclei (AGNs). Two objects fallin the region of galaxies with bright PAH (polycyclic aromatichydrocarbon) emission: one in [4.5] − [5.8] vs. [5.8] − [8.0]colour-colour diagram (Fig. 14b) and one in [3.6] − [5.8] vs. [4.5] − [8.0] colour-colour diagram (Fig. 14c). We did not findany shock emission knots. Five objects, according to criteriaof Gutermuth et al. (2009), may be contaminated by satu-rated PAH emission objects (Fig. 14c). All these objects, arenot included in any catalogue of AGNs or galaxies and they c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 K =2 mag AGN3243217 9(a) [ . ] [4.5] - [8.0] -0.5 0 0.5 1 1.5-0.5 0 0.5 1 1.5 2PAH(b) 32432A K =5 mag [ . ] - [ . ] [5.8] - [8.0]17 9 -0.5 0 0.5 1 1.5 2 2.5-0.5 0 0.5 1 1.5 2 2.5 3A K =2 mag PAH(c) Class II 3243217 [ . ] - [ . ] [4.5] - [8.0] 9-0.5 0 0.5 1 1.5-0.5 0 0.5 1 1.5Shock emission Class IPAH contam. ap.3 243A K =2 mag(d) [ . ] - [ . ] [4.5] - [5.8]217 9 -0.5 0 0.5 1 1.5 2 2.5 3-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2Class IClass II2 317 243 ( K S - [ . ] ) ([3.6] - [4.5]) Figure 14.
Spitzer /IRAC colour-magnitude diagram and colour-colour diagrams used for the selection of Class I (red dots) and Class II (greendots) objects and for the isolation of the extragalactic sources (white squares, see Sect. 5.1 for more details). Dark dots represent Class III objectsand/or field stars. Three crossed Class I objects does not fulfil the colour restriction for being a protostar ([4.5]–[24] > are very close to restriction lines in colour-magnitude andcolour-colour diagrams, so they are probably not extragalacticsources.The JHK S photometry was taken from 2MASS All-SkyCatalog of Point Sources of Cutri et al. (2003). For 3098 ourstars we found counterparts among 2MASS sources in thesearch radius of 2 (cid:48)(cid:48) , 1517 of them have photometric uncer-tainty σ < . mag in all three bands, and 653 have coun-terparts in the catalogue of Balog et al. (2007) (605 of themhave σ < . mag).The Spitzer and 2MASS magnitudes for variable stars areshown in Table A2 in Appendix. After checking for extragalactic objects, we identifiedClass II objects using restrictions in [4.5]–[8.0] and[3.6] − [5.8] colours (shown in Fig. 14c), and with[3.6] − [4.5] − σ ([3.6] − [4.5]) > − [5.8] and [3.6] − [4.5] colours greater than 0.7were classified as Class I. We found one such source,variable243 , that fulfil these colour restrictions (Fig. 14d).Some additional YSOs can be found from the constraintsof the dereddened ([3.6] − [4.5]) and ( K S − [3.6]) coloursderived according to procedure described in Appendix A.2. ofGutermuth et al. (2009). Originally, this method was appliedto the stars without [5.8] and/or [8.0] µ m photometry whichhave good quality ( σ < . mag) H , K S and/or J photometry.Although all our stars with Spitzer data have photometry in allfour IRAC bands, we apply this method to check if we can findsome additional Class I and Class II objects.This way we found 4 additional Class I candidates The full version of Table A2 is available in electronic form from theCDS. The numbers indicate the variables we found, listed in Table A1 -0.5 0 0.5 1 1.5 -1 0 1 2 3 4 5 6 7 8A K =5 mag [ . ] - [ . ] [4.5] - [24] 3 243217 9(a)-0.5 0 0.5 1 1.5 -1 0 1 2 3 4 5 6 7 8A K =5 mag [ . ] - [ . ] [5.8] - [24]217 3243 9(b) Figure 15.
Spitzer /IRAC and MIPS colour-colour diagrams used forthe selection of transition disk objects (blue circles). The colouredsymbols are the same as in Fig. 14. The arrow shows the extinctionvector for A K = 5 mag (Flaherty et al. 2007). (Fig. 14e) and 23 additional Class II candidates. Out of these23 objects, 12 stars which have [4 . − [24] > . mag and [5 . − [24] > . mag (or [4 . − [8 . > . mag for objectswithout [24] µ m band photometry), we classified as Class IIobjects.All objects selected as protostars must have [5 . − [24] colour greater than 4 mag. Two objects (variables 2 and 17)found previously as Class I do not meet this condition andfor one object there are no [24]-band photometry. They aremarked with crosses in Fig. 14 −
16. Finally, using
Spitzer and2MASS photometry, we found two Class I objects (variable 3and 243) and 227 Class II objects. c (cid:13) , 1–, 1–
Spitzer and2MASS photometry, we found two Class I objects (variable 3and 243) and 227 Class II objects. c (cid:13) , 1–, 1– ?? G. Michalska K =1 mag39243217 K S K S - [24] Figure 16. K S vs. K S − [24] colour-magnitude diagram for observedstars in NGC 2244. Dotted lines denote the divisions between Class I,flat spectrum, Class II, and Class III objects (Rebull et al. 2007). Thearrow shows the extinction vector for A K = 1 mag (Flaherty et al.2007). Symbols for YSOs are the same as in Fig. 14. Additionally,encircled symbols represent HAeBe stars (Park & Sung 2002), pinkdots – flat spectrum object with − . < α IRAC < . , field stars aremarked with brown dots. Another class of YSOs are transition disk objects which donot show near- and mid-infrared excess. These sources can befound with the use of [24] µ m MIPS photometry. We used theapproach of Megeath et al. (2012) who considered objectswith [8]–[24] colours greater than 2.5 mag and the dered-dened [3.6]–[4.5] colours smaller than 0.2 mag as transitiondisk object. This way, among 167 objects with MIPS photom-etry, we found 14 transition disk objects (7 of them are vari-able). They are marked in blue in Fig. 14–16. Most of the remaining 426 objects which were not classifiedas Class I, Class II or transition disks are Class III objects (disk-less YSOs) and/or field stars (pure photosphere), 84 of themare variable. It is difficult to distinguish between these twogroups. One way was presented by Rebull et al. (2007) whoused K S vs. K S − [24] colour magnitude diagram. The authorsestablished the ranges of K S − [24] colour for Class I (8.31 − − − < K S − [24] = 2 mag.The K S vs. K S − [24] colour magnitude diagram for starsin the observed field is shown in Fig. 16. In this diagram YSOsfound using the selection criteria of Gutermuth et al. (2009)are shown. As can be seen in the figure, none of Class I starhave K S − [24] > . mag. Both Class I objects togetherwith 8 Class II objects have K S − [24] between 6.75 and 8.31mag. According to colour criteria of Rebull et al. (2007) theyare YSOs with flat spectrum. The encircled symbols in Fig. 16represent HAeBe stars (Park & Sung 2002). One of them, star -0.5 0 0.5 1 1.5 2-1 0 1 2 3 4 5 6 [ . ] - [ . ] [4.6] - [12]Class IClass II 3 Figure 17.
WISE colour-colour diagram used for the selection ofClass I and Class II objects base on restrictions of Koenig & Leisawitz(2014). Green symbols represent Class II sources: circles – commonfrom WISE and IRAC, squares – only from WISE, triangles – only fromIRAC. Red circle indicate Class I object. Black points are Class III/fielsstars, grey points – sources that may be extragalactic contaminants.
3, according to criteria of Gutermuth et al. (2009), was clas-sified as Class I object and the other HAeBe star, star 2, wasclassified as Class II object. Third HAeBe star, star 9, are inthe area of sources contaminated by saturated PAH emissionobjects (Fig. 14d)For three stars K S − [24] is between 2 and 3.37 and theyare probably diskless YSOs. We found that 22 stars have K S − [24] < mag and 21 of them have K S − [24] < mag.The position of YSOs in the map of the sky is shownin Fig. 18. The objects of all classes are distributed homo-geneously, without any concentration. α The classes of YSOs, described in the introduction of this sec-tion, were defined based on α spectral index. We computed α indexes, from the slope of the linear fit to the observed fluxesbetween the IRAC [3.6] µ m band and the IRAC [8.0] µ m band( α IRAC ), as it is quite insensitive to extinction (Muench et al.2007). The α indexes of the variable stars are given in TableA1 in Appendix.Since α index of HAeBe star 3, classified in Sect. 5.1.1as Class I, is less then 0.3, it is rather flat spectrum object.Four other objects which have α between − . and . , weclassified as flat spectrum. They are marked with pink dots inFig. 16. One object with α = − . and K S − [24] between6.75 and 8.31 mag we also classified as flat spectrum. For theother Class I object, star 243, the α index is equal to 0.98 con-firms its previous classification. Another object, HAeBe star 9,also have α index greater then 0.3, such as Class I objects, butaccording to colours restrictions of Gutermuth et al. (2009) isclassified as object contaminated by PAH emission. The α in-dexes of almost all Class II YSOs found in Sect. 5.1.1, whichare between -1.8 and -0.3, confirmed their classification. Since not for all our variable stars we found
Spitzer coun-terparts, we identify YSOs based on WISE (Wide-field In-frared Survey Explorer, Wright et al. 2010) photometry aswell. This photometry was obtained in in four mid-infrared c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure 18.
Spatial distribution for Class I object (red square), Class II objects (green circles), flat spectrum objects (magenta rhombus) andtransition objects (blue rhombus) found from
Spitzer and 2MASS photometry (Sect. 5).
Table 4.
Number of YSOs found in observed field.Objects total variableClass I 1 1Class I/ Flat spectrum 1 1Flat spectrum
10 3Class II 219 89Transition disks 14 7Class III 426 84 objects classified based on α index; objects classified based on K S − [24] colour. bands: [3.4], [4.6], [12], and [22] µ m. Using ALLWISE cata-log (Cutri & et al. 2014) we found 1804 counterparts in thesearch radius of 2 (cid:48)(cid:48) . In order to find YSOs, to the sourceswith error less then 0.2 mag in [3.4], [4.6] and [12] µ mband, we applied the colour and brightness constraints de-scribed in Koenig & Leisawitz (2014). In this way we foundonly one Class I object (star 3) and 9 additional Class II ob-jects (marked with squares in Fig. 17), 3 of them are vari-able. From the slope of the linear fit to the observed fluxesin WISE [3.4], [4.6] and [12] µ m band, we calculated α in-dexes ( α WISE ). The classes of objects and α WISE indexes arewritten in brackets in Table A1.The total number of YSOs found in observed field aresummarized in Table 4.
The variable PMS stars found in Sect. 3.3 and 3.4 may beWTTSs, CTTSs or HAeBe stars. Their position in colour–magnitude and colour–colour diagrams, near- and mid-IR ex-cess as well as the properties of Hα emission line help to un-derstand the possible origin of their variability. Therefore, ad-ditional archival data of the IPHAS (Isaac Newton TelescopePhotometric H-Alpha Survey) and UKIDSS (United KingdomInfrared Deep Sky Survey) surveys were used in our analysis. Combination of IPHAS ( r (cid:48) − i (cid:48) ) and ( r (cid:48) − Hα ) colour indicesallowed to find stars with H α in emission. The method wasdescribed by Drew et al. (2005) and Barentsen et al. (2011).The authors provide a grid of colour tracks for stars with dif-ferent Hα emission equivalent widths (EW H α ), spectral typesand reddenings. We found r (cid:48) , i (cid:48) and Hα -band photometryfor about 3700 our objects using IPHAS DR2 catalogue (Bar-entsen et al. 2014) in the search radius of 1 (cid:48)(cid:48) .For 226 variables found in our photometry we identifiedIPHAS counterparts with photometric errors smaller than 0.1mag in all three bands. They are shown in the ( r (cid:48) − Hα ) vs. ( r (cid:48) − i (cid:48) ) colour-colour and r (cid:48) vs. ( r (cid:48) − i (cid:48) ) colour-magnitudediagrams in Fig. 19 and 20, respectively. In order to find CTTScandidates based on ( r (cid:48) − i (cid:48) ) and ( r (cid:48) − Hα ) colours, we usedthe selection threshold described by Barentsen et al. (2011).For early type stars, this threshold (red line in Fig. 19) is thesame as unreddened 10 ˚A track, but for stars later than M0the empirical threshold from Barrado y Navascu´es & Mart´ın c (cid:13) , 1– ?? G. Michalska r ’ − H α r’ − i’ O5 A0 F0 K0 K5 M0 M2 M3 M4200Å100Å10Å giantsMS5 18 75 92 4817020539 1715
Figure 19.
IPHAS ( r (cid:48) − Hα ) vs. ( r (cid:48) − i (cid:48) ) colour-colour diagram for theobserved field. The symbols indicate variable stars found in this pa-per: pulsating (red squares), eclipsing (pink diamonds), HAeBe (or-ange triangles), other periodic (green circles) and irregular (blue cir-cles). Synthetic tracks for MS stars and giants (solid black and bluelines), and for stars with photometric EW H α = 10, 100 and 200 ˚A forspectral types O5–M6 (dashed blue lines), shifted according to red-dening vector for A V = 1 . mag (blue arrow), were taken fromBarentsen et al. (2011). Red line is the selection threshold for CTTSs. (2003) was taken. We found 143 objects above the thresh-old. Out of them, 30 variable stars lie above the thresholdwith 3 σ confidence level defined by Barentsen et al. (2011).They are notified with the letters ”IA” in Table A1 in Appendix.The other stars above the reddened ( E ( B − V ) = 0 . mag)10 ˚A track and the objects lying between 0 and 10 ˚A track aremarked in Table A1 as ”Ia” and ”Ib”, respectively. As can beseen in Fig. 19, most of the variables with strong Hα emissionhave spectral types later than K0. Only two stars above CTTSthreshold with spectral type earlier than K0, star 3 and 9,are HAeBe stars reported by Park & Sung (2002). The IPHASmagnitudes for variable stars are listed in Table A2 in Ap-pendix. The colour-colour diagram of near-infrared
JHK photometryis the other useful tool for understanding YSOs. Therefore,we decided to use UKIDSS (United Kingdom Infrared DeepSky Survey) photometry as it is more accurate than 2MASSphotometry. The UKIDSS photometry was obtained with theUnited Kingdom InfraRed Telescope (UKIRT) during GalacticPlane Survey. Almost for all objects we observed, we found J , H and K photometry in the UKIDSS-DR6 catalogue (Lu-cas et al. 2008), assuming a search radius of 1 (cid:48)(cid:48) . The JHK
UKIDSS magnitudes for variable stars are shown in Table A2in the Appendix.The ( J − H ) vs. ( H − K ) diagram for variable starsfound in Sect. 3 is shown in Fig. 21. The dashed line repre-sents the locus of CTTSs determined by Meyer et al. (1997).Since this line was derived in the CIT (California Institute ofTechnology) system, we transformed UKIDSS photometry to2MASS photometry according to the transformation relationsof Hewett et al. (2006) and then to CIT photometry using re-lations described by Carpenter on ”2MASS Color Transforma-
12 13 14 15 16 17 18 19 20 0 0.5 1 1.5 2 2.5 r ’ r’ - i’
19 485472 1702051539 175 18 7592
Figure 20.
IPHAS r (cid:48) vs. ( r (cid:48) − i (cid:48) ) colour-magnitude diagram for theobserved field. The symbols are the same as in Fig. 19. The ZAMSrelation for Z=0.02 (solid line) was taken from Siess et al. (2000).The isochrones (dotted lines) for 0.1, 0.5, 1, 2, 6, 10, and 100 Myr foradopted A V = 1 . mag and ( m − M V ) = 11 . mag were takenfrom Bressan et al. (2012). tions” web page . If the brightness of the star in UKIDSS-DR6catalogue is flagged as ”close to saturated”, we show 2MASScolours, transformed to CIT system in Fig. 21.The solid black line in Fig. 21, taken from Pecaut &Mamajek (2013) , represents the ZAMS and the solid blueline, taken from Bessell & Brett (1988), denote colours forlate-type giants. The arrow shows the reddening vector for A V = 1 . mag. The extinction ratios A J /A V = 0 . , A H /A V = 0 . and A K /A V = 0 . we adopted fromRieke & Lebofsky (1985). The blue rectangle is the area ofdereddened ( J − H ) and ( H − K ) colours for HAeBe stars,defined by Hern´andez et al. (2005). As can be seen in this fig-ure, five variable stars we found fall into this box. They willbe discussed in Sect. 6.3.We identified 208 stars of Class II lying above CTTS locus,88 of them are variable. Only 20 of Class II objects lie belowCTTS line, four of them (2, 9, 15, 17) are variables in HAeBebox in the ( J − H ) vs. ( H − K ) diagram (Fig. 21).Following Sugitani et al. (2002) we have drawn threelines parallel to the reddening vector: from the tip (spec-tral type M4) of the giant branch (left line), from the point ( H − K ) , ( J − H ) = (0 . , . mag for spectral type A0 of theMS (middle line), and from the tip of the intrinsic CTTS line(right line). The objects lying between left and middle line,marked with ”F” in Table A1 in Appendix, are either field stars(main-sequence stars or giants) or Class III/Class II sourceswith small near-infrared (NIR) excesses (Ojha et al. 2004). (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4CTTSF T PHAeBe stars J - H H - KO3 B8F0G0K0K5M0 M4 M9 6 2 3915 17
Figure 21.
The ( J − H ) vs. ( H − K ) UKIDSS colour-colour diagramfor the observed field. The symbols are the same as in Fig. 19. Thedashed line is the locus of CTTSs (Meyer et al. 1997). Solid blackand blue lines denote intrinsic colours for ZAMS and late-type giants,respectively. The arrow shows the reddening vector for A V = 1 . mag. All the measurements were transformed to the CIT system. The sources lying between middle and right line, marked with”T” in Table A1 in Appendix, are considered to be Class IIsources (mostly CTTSs) with large NIR excesses or HerbigAe/Be stars with small NIR excess. The sources lying red-wards of ”T” region are most likely Class I objects (protostars)or Herbig Ae/Be stars.
The age spread of PMS stars in NGC 2244 estimated by Park& Sung (2002) is between 0.1 − − ( J − H ) vs. ( H − K ) diagram(Fig. 21). We classified this star as HAeBe Class I/flat spec-trum object. The other two stars falling into the HAeBe box(Fig. 21) are stars 15 and 17. The photometric EW H α derivedfrom IPHAS photometry of three HAeBe candidates (star 3,9, and 17) is greater than 10 ˚A. For star 15, the photometricEW H α is between 0 and 10 ˚A.A common feature of classical T Tauri stars (CTTSs) is theequivalent width of H α (EW H α ) emission line greater than10 ˚A. Using IPHAS photometry we have found 68 variableslying above the 10 ˚A track (”IA” and ”Ia” in Table A1). Mostof them, 45 stars, are Class II objects, 43 of them have spec-tral types, estimated from ( r (cid:48) − i (cid:48) ) and ( r (cid:48) − Hα ) colours (Fig. 19) later than K0 and lie above CTTS locus in ( J − H ) vs. ( H − K ) diagram (Fig. 21). They are the best candidatesfor CTTS stars and are marked as CTTS in Table A1 in Ap-pendix. Excellent candidates for CTTSs are also four starswith EW H α < ˚A which large infrared excess placed themin ”T” region in Fig. 21 and one Class I object, star 243.Among 48 Class III/field stars, that lie above the 10 ˚AEW H α track in Fig. 19, 36 stars occupy the region of FGK typemain sequence stars, with ( J − H ) < . mag. Seven of them,marked as MS in Table A1, are variable. The remaining twelvestars can be CTTSs as they lie above CTTSs locus in Fig. 21.Nine of them, marked as CTTS (cid:63) in Table A1, are variable.The position of selected CTTS candidates in r (cid:48) vs. ( r (cid:48) − i (cid:48) ) colour-magnitude diagram (Fig. 20) is typical for PMSs. Onlyone star, 222, lie in this diagram close to ZAMS and is placedabove 200 ˚A track in Fig. 19. It may be an active field star,but its position in the V vs. ( V − I C ) diagram a little above10 Myr isochrone and the membership probability, equal to74.3%, does not exclude it from the members of the cluster.Our classification of other Class II variables lying aboveCTTS locus in Fig. 21 with photometric EW H α < dependson their spectral index α . Lada et al. (2006) found that ob-jects with thick disks, typical for CTTSs, are characterised byspectral index α > − . . They also found that large fraction(64%) of WTTSs are diskless stars ( α < − . ) and about22% of WTTSs have thin disks ( − . < α < − . ). Forthis reason, we marked the stars with α > − . as CTTS (cid:63) in Table A1 and stars with α < − . as WTTS. The ClassIII variables lying above CTTS locus in Fig. 21 and havingEW H α between 0 and 10 were also classified as WTTS. Theremaining variable stars lying above CTTS line were classifiedas WTTS (cid:63) . This way, we have found 97 candidates for CTTSstars (49 CTTS and 48 CTTS (cid:63) ), 68 candidates for WTTS stars(32 WTTS and 36 WTTS (cid:63) ) and 6 candidates for HAeBe stars(4 of them were known before).Common feature of YSOs is emission in X-rays. Usingcatalogue of X-ray sources from Chandra published by Wanget al. (2008), we identified 482 counterparts in the search ra-dius of 1 (cid:48)(cid:48) , 182 of them are variable stars. They are markedwith letters ”a”, ”b” or ”c” in Table A1 in Appendix, followingthe notification used by Wang et al. (2008) indicating vari-ability characterization.Park & Sung (2002) found ROSAT HRI X-ray counter-parts for sixteen stars in NGC 2244. They classified six ofthem as PMS stars. Four of them (star 10, 13, 14, and 16)are variable in our photometry. The authors denoted two ob-jects as ”PMS X-ray binary”, one of them is variable star in ourdata (star 49). Park & Sung (2002) also selected 14 PMS starand seven PMS candidates based on the strength of H α emis-sion line. Since the authors published the positions of starsbrighter than 17 mag, we have found only seven counterparts.Six of them, marked with letters ”PS” in Table A1, are variablestars.Bergh¨ofer & Christian (2002) published the results for138 X-ray sources in NGC 2244 selected from ROSAT PSPCand HRI observations. The majority of them have strong H α emission. Out of them 38 stars are variable in our photometry.They are marked with letters ”BC” in Table A1.On average, the amplitudes of light curve variations ofCTTSs are larger than those of WTTSs (Lata et al. 2012).The variability of CTTSs is usually irregular, caused by ac-cretion processes and the changes in their disks. The changes c (cid:13) , 1– ?? G. Michalska li gh t c u r v e R M S [ m ag ] [3.6 ] - [4.5] Figure 22.
The V-filter light curves RMS (variability amplitude) as afunction of
Spitzer [3.6] − [4.5] colour for periodic (dots) and irreg-ular (triangles) variables. The colours represent variable stars: CTTS(red), CTTS (cid:63) (green), WTTS (dark blue), and WTTS (cid:63) (light blue),described in Sect. 6.3. Dashed line is the boundary between disklessand disked stars ([3.6] − [4.5] = in light curves of WTTSs are often periodic, caused by coolspots. Dutta et al. (2018) show that variability amplitude ofstars with infrared excess is larger for those that have disks.Following the authors, we calculated the observed root meansquare (RMS= σ obs ) in the light curves, expressed as: σ = n (cid:80) ni =1 w i ( m i − ¯ m ) ( n − (cid:80) ni =1 w i , (10)where m i and ¯ m are respectively individual and average V -filter magnitudes, and w i = 1 . /σ i is the weight assigned toeach observation with photometric uncertainties σ i . The RMSas a function of [3.6] − [4.5] colour is shown in Fig. 22. Ascan be seen in this figure, most stars classified as CTTS orCTTS (cid:63) have larger amplitudes then WTTSs. They also havethe [3.6] − [4.5] colours greater than 0.25 mag which means,according to Dutta et al. (2018), they are disked stars. We presented multi-wavelength photometric study of youngopen cluster NGC 2244. Using
UBV I C photometry we haveidentified 245 variable stars. The time series photometry ofonly one of them was published before. Based on near- andmid-infrared excess and photometric equivalent width of Hα emission line we classify PMS variables. Among 211 stars ir-regular stars we have found 96 CTTS candidates, 54 WTTScandidates and 6 HAeBe stars. We have also identified 23periodic variables with periods greater than one day. Four-teen of them we have classified as WTTS candidates and onestar as CTTS (cid:63) candidate. The relation between mass of thestar and its rotational period found in many young open clus-ters, e.g. NGC 2264, NGC 7380, NGC 1893 and Be 59 is notvisible in our sample of periodic variables. We have shownthat stars with infrared excess have, on average, higher ampli-tudes. Similar tendency was found in NGC 2282 (Dutta et al.2018).We have found four new δ Scuti stars. All of them arelikely non-members. In the observed field there is one starreported in the literature as β Cephei-type star. The small amplitude of its variability is however below our detectionthreshold. Unfortunately, the saturation of bright stars makesimpossible to verify if in such a young cluster there are any β Cephei or SPB stars.In addition to the well-known eclipsing binary V578Mon, we have found six other eclipsing systems. Two of themare probably the cluster members.Based on
Spitzer , UKIDSS, 2MASS and WISE photometrywe have identified YSOs in our photometry. As a result, onevariable was classified as Class I object, one as Class I/flatspectrum object, 91 as Class II objects, 4 as flat spectrumsources and 7 as transition disk objects. In comparison to Ba-log et al. (2007) we have identified small number of ClassI objects. This is due to the fact that we classified only thesources detected from our photometry, while most of theseobjects are not visible in the optical bands.Due to the short period of observations, we were not ableto find variable PMS stars such as UXors, FUors or EXors,although some candidates were found to have the range ofvariations greater than 1 mag and the shape of light curvessimilar to those type of variables. It is not out of the questionthat some of our HAeBe stars could be classified as UXors, andsome of our identified CTTSs as FUors or EXors, in the future.A large number of identified PMS variable stars (165 TTSand 6 HAeBe stars) can be used to verify models of PMS stars.Since the variability of WTTSs is caused by cool spots, the am-plitudes, periods and shape of light curves can change overtime (Cohen et al. 2004). It would be interesting to checktheir variability after several years. Some additional observa-tion can also be useful to check variability among the remain-ing Class II objects: to find the periods of long period variablesand to verify the existence of early-type pulsating stars.
ACKNOWLEDGEMENTS c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 the University of California, Los Angeles, and the Jet Propul-sion Laboratory/California Institute of Technology, funded bythe National Aeronautics and Space Administration.This publication makes use of data products from theTwo Micron All Sky Survey, which is a joint project of theUniversity of Massachusetts and the Infrared Processing andAnalysis Center/California Institute of Technology, funded bythe National Aeronautics and Space Administration and theNational Science Foundation.This publication makes use of data products from theWide-field Infrared Survey Explorer, which is a joint project ofthe University of California, Los Angeles, and the Jet Propul-sion Laboratory/California Institute of Technology, funded bythe National Aeronautics and Space Administration.This research has also made use of IRAF. IRAF is dis-tributed by the National Optical Astronomy Observatory,which is operated by the Association of Universities for Re-search in Astronomy, Inc., under cooperative agreement withthe National Science Foundation.This work has made use of data from theEuropean Space Agency (ESA) mission Gaia
Gaia
Gaia
Multilateral Agreement.We are indebted to Prof. Andrzej Pigulski and Przemy-saw Mikoajczyk for his comments made upon reading themanuscript. We thank Ewa Niemczura, Stefan Meingast andIvanka Stateva who helped to carry out some additional ob-servations which were, however, not included to the analysis.
REFERENCES
Allen L., Megeath S. T., Gutermuth R., Myers P. C., WolkS., Adams F. C., Muzerolle J., Young E., Pipher J. L., 2007,Protostars and Planets V, pp 361–376Allen L. E., Calvet N., D’Alessio P., Merin B., Hartmann L.,Megeath S. T., Gutermuth R. A., Muzerolle J., Pipher J. L.,Myers P. C., Fazio G. G., 2004, ApJS, 154, 363Andre P., Ward-Thompson D., Barsony M., 1993, ApJ, 406,122Artemenko S. A., Grankin K. N., Petrov P. P., 2010, Astron-omy Reports, 54, 163Bagnulo S., Hensberge H., Landstreet J. D., Szeifert T., WadeG. A., 2004, A&A, 416, 1149Balog Z., Muzerolle J., Rieke G. H., Su K. Y. L., Young E. T.,Megeath S. T., 2007, ApJ, 660, 1532Baran A. S., Koen C., Pokrzywka B., 2015, MNRAS, 448, L16Barentsen G., Farnhill H. J., Drew J. E., Gonz´alez-SolaresE. A., Greimel R., Irwin M. J., Miszalski B., Ruhland C.,Groot P., Mampaso A., Sale S. E., Henden A. A., Aungwero-jwit A., Barlow M. J., Carter P. J., Corradi R. L. M., et al.2014, MNRAS, 444, 3230Barentsen G., Vink J. S., Drew J. E., Greimel R., Wright N. J.,Drake J. J., Martin E. L., Valdivielso L., Corradi R. L. M.,2011, MNRAS, 415, 103Barrado y Navascu´es D., Mart´ın E. L., 2003, AJ, 126, 2997Bell C. P. M., Naylor T., Mayne N. J., Jeffries R. D., LittlefairS. P., 2013, MNRAS, 434, 806 Bergh¨ofer T. W., Christian D. J., 2002, A&A, 384, 890Bessell M. S., Brett J. M., 1988, PASP, 100, 1134Bonatto C., Bica E., 2009, MNRAS, 394, 2127Bouvier J., Cabrit S., Fernandez M., Martin E. L., MatthewsJ. M., 1993, A&A, 272, 176Bressan A., Marigo P., Girardi L., Salasnich B., Dal Cero C.,Rubele S., Nanni A., 2012, MNRAS, 427, 127Briquet M., Aerts C., Baglin A., Nieva M. F., Degroote P.,Przybilla N., Noels A., Schiller F., Vuˇckovi´c M., Oreiro R.,Smolders K., Auvergne M., Baudin F., Catala C., Michel E.,Samadi R., 2011, A&A, 527, A112Caldwell J. A. R., Cousins A. W. J., Ahlers C. C., van WamelenP., Maritz E. J., 1993, South African Astronomical Observa-tory Circular, 15, 1Chen L., de Grijs R., Zhao J. L., 2007, AJ, 134, 1368Chini R., Hoffmeister V. H., Nasseri A., Stahl O., ZinneckerH., 2012, MNRAS, 424, 1925Cohen R. E., Herbst W., Williams E. C., 2004, AJ, 127, 1602Cutri R. M., et al. 2014, VizieR Online Data Catalog, 2328Cutri R. M., Skrutskie M. F., van Dyk S., Beichman C. A.,Carpenter J. M., Chester T., Cambresy L., Evans T., FowlerJ., Gizis J., Howard E., Huchra J., Jarrett T., Kopan E. L.,Kirkpatrick J. D., Light R. M., Marsh K. A. e. a., 2003, VizieROnline Data Catalog, 2246, 0D´ıaz-Fraile D., Rodr´ıguez E., Amado P. J., 2014, A&A, 568,A32Drew J. E., Greimel R., Irwin M. J., Aungwerojwit A., BarlowM. J., Corradi R. L. M., Drake J. J., G¨ansicke B. T., Groot P.,Hales A., Hopewell E. C., Irwin J., Knigge C., Leisy P., 2005,MNRAS, 362, 753Dutta S., Mondal S., Joshi S., Jose J., Das R., Ghosh S., 2018,MNRAS, 476, 2813Flaherty K. M., Pipher J. L., Megeath S. T., Winston E. M.,Gutermuth R. A., Muzerolle J., Allen L. E., Fazio G. G.,2007, ApJ, 663, 1069Gaia Collaboration Brown A. G. A., Vallenari A., Prusti T., deBruijne J. H. J., Babusiaux C., Bailer-Jones C. A. L., 2018,ArXiv e-printsGaia Collaboration Prusti T., de Bruijne J. H. J., BrownA. G. A., Vallenari A., Babusiaux C., Bailer-Jones C. A. L.,Bastian U., Biermann M., Evans D. W., et al. 2016, A&A,595, A1Garcia E. V., Stassun K. G., Hebb L., G´omez Maqueo ChewY., Heiser A., 2011, AJ, 142, 27Garcia E. V., Stassun K. G., Pavlovski K., Hensberge H.,G´omez Maqueo Chew Y., Claret A., 2014, AJ, 148, 39Greene T. P., Wilking B. A., Andre P., Young E. T., Lada C. J.,1994, ApJ, 434, 614Gruber D., Saio H., Kuschnig R., Fossati L., Handler G.,Zwintz K., Weiss W. W., Matthews J. M., Guenther D. B.,Moffat A. F. J., Rucinski S. M., Sasselov D., 2012, MNRAS,420, 291Gutermuth R. A., Megeath S. T., Myers P. C., Allen L. E.,Pipher J. L., Fazio G. G., 2009, ApJS, 184, 18Henderson C. B., Stassun K. G., 2012, ApJ, 747, 51Hensberge H., Pavlovski K., Verschueren W., 2000, A&A,358, 553Herbig G. H., 1960, ApJS, 4, 337Herbig G. H., 1977, ApJ, 217, 693Herbig G. H., 1989, in Reipurth B., ed., European SouthernObservatory Conference and Workshop Proceedings Vol. 33of European Southern Observatory Conference and Work- c (cid:13) , 1– ?? G. Michalska shop Proceedings, FU Orionis eruptions.. pp 233–246Herbst W., Herbst D. K., Grossman E. J., Weinstein D., 1994,AJ, 108, 1906Herbst W., Maley J. A., Williams E. C., 2000, AJ, 120, 349Hern´andez J., Calvet N., Hartmann L., Brice˜no C., Sicilia-Aguilar A., Berlind P., 2005, AJ, 129, 856Hewett P. C., Warren S. J., Leggett S. K., Hodgkin S. T., 2006,MNRAS, 367, 454Huang W., Gies D. R., 2006, ApJ, 648, 580Koenig X. P., Leisawitz D. T., 2014, ApJ, 791, 131Kurosawa R., Romanova M. M., 2013, MNRAS, 431, 2673Kuznetsov V. I., 1986, Kinematika i Fizika Nebesnykh Tel, 2,45Lada C. J., 1987, in Peimbert M., Jugaku J., eds, Star Form-ing Regions Vol. 115 of IAU Symposium, Star formation -From OB associations to protostars. pp 1–17Lada C. J., Muench A. A., Luhman K. L., Allen L., HartmannL., Megeath T., Myers P., Fazio G., Wood K., Muzerolle J.,Rieke G., Siegler N., Young E., 2006, AJ, 131, 1574Lamm M. H., Mundt R., Bailer-Jones C. A. L., Herbst W.,2005, A&A, 430, 1005Lata S., Pandey A. K., Chen W. P., Maheswar G., Chauhan N.,2012, MNRAS, 427, 1449Li J. Z., Wu C. H., Chen W. P., Rector T., Chu Y. H., Ip W. H.,2002, AJ, 123, 2590Lucas P. W., Hoare M. G., Longmore A., Schr¨oder A. C., DavisC. J., Adamson A., Bandyopadhyay R. M., de Grijs R., SmithM., Gosling A., Mitchison S., G´asp´ar A., Coe M., Tamura M.,Parker Q. e. a., 2008, MNRAS, 391, 136Mahy L., Naz´e Y., Rauw G., Gosset E., De Becker M., SanaH., Eenens P., 2009, A&A, 502, 937Marschall L. A., van Altena W. F., Chiu L.-T. G., 1982, AJ, 87,1497Mason B. D., Wycoff G. L., Hartkopf W. I., Douglass G. G.,Worley C. E., 2001, AJ, 122, 3466Massey P., Johnson K. E., Degioia-Eastwood K., 1995, ApJ,454, 151Megeath S. T., Allen L. E., Gutermuth R. A., Pipher J. L.,Myers P. C., Calvet N., Hartmann L., Muzerolle J., FazioG. G., 2004, ApJS, 154, 367Megeath S. T., Allgaier E., Young E., Allen T., Pipher J. L.,Wilson T. L., 2009, AJ, 137, 4072Megeath S. T., Gutermuth R., Muzerolle J., Kryukova E., Fla-herty K., Hora J. L., Allen L. E., Hartmann L., Myers P. C.,Pipher J. L., Stauffer J., Young E. T., Fazio G. G., 2012, AJ,144, 192Meyer M. R., Calvet N., Hillenbrand L. A., 1997, AJ, 114,288Michalska G., 2014, in Guzik J. A., Chaplin W. J., HandlerG., Pigulski A., eds, Precision Asteroseismology Vol. 301 ofIAU Symposium, Variable stars in the young open clusterNGC 2244. pp 453–454Muench A. A., Lada C. J., Luhman K. L., Muzerolle J., YoungE., 2007, AJ, 134, 411Ogura K., Ishida K., 1981, PASJ, 33, 149Ojha D. K., Tamura M., Nakajima Y., Fukagawa M., SugitaniK., Nagashima C., Nagayama T., Nagata T., Sato S., Vig S.,Ghosh S. K., Pickles A. J., Momose M., Ogura K., 2004, ApJ,616, 1042Park B.-G., Sung H., 2002, AJ, 123, 892Pecaut M. J., Mamajek E. E., 2013, ApJS, 208, 9Pickles A., Depagne ´E., 2010, PASP, 122, 1437 Pojma´nski G., 2003, Acta Astronomica, 53, 341Pribulla T., Rucinski S. M., Kuschnig R., Ogłoza W., PileckiB., 2009, MNRAS, 392, 847Pribulla T., Rucinski S. M., Latham D. W., Quinn S. N., Si-wak M., Matthews J. M., Kuschnig R., Rowe J. F., GuentherD. B., Moffat A. F. J., Sasselov D., Walker G. A. H., WeissW. W., 2010, Astronomische Nachrichten, 331, 397Rebull L. M., Stapelfeldt K. R., Evans II N. J., Jørgensen J. K.,Harvey P. M., Brooke T. Y., Bourke T. L., Padgett D. L.,Chapman N. L., Lai S.-P., Spiesman W. J., Noriega-CrespoA., Mer´ın B., Huard T., Allen L. E., Blake G. A. e. a., 2007,ApJS, 171, 447Rieke G. H., Lebofsky M. J., 1985, ApJ, 288, 618Ripepi V., Cusano F., di Criscienzo M., Catanzaro G., Palla F.,Marconi M., Ventura P., Neiner C., Catala C., Bernabei S.,2011, MNRAS, 416, 1535Rodr´ıguez E., Breger M., 2001, A&A, 366, 178Samus N. N., Durlevich O. V., et al. 2009, VizieR Online DataCatalog, 1, 2025Sanders W. L., 1971, A&A, 14, 226Sariya D. P., Yadav R. K. S., Bellini A., 2012, A&A, 543, A87Semkov E. H., 2011, Bulgarian Astronomical Journal, 15, 65Siess L., Dufour E., Forestini M., 2000, A&A, 358, 593Stetson P. B., 1987, PASP, 99, 191Stetson P. B., 1992, in Worrall D. M., Biemesderfer C., BarnesJ., eds, Astronomical Data Analysis Software and SystemsI Vol. 25 of Astronomical Society of the Pacific ConferenceSeries, More Experiments with DAOPHOT II and WF/PCImages. p. 297Sugitani K., Tamura M., Nakajima Y., Nagashima C., Na-gayama T., Nakaya H., Pickles A. J., Nagata T., Sato S.,Fukuda N., Ogura K., 2002, ApJ, 565, L25Vasilevskis S., Klemola A., Preston G., 1958, AJ, 63, 387Wang J., Townsley L. K., Feigelson E. D., Broos P. S., GetmanK. V., Rom´an-Z´u˜niga C. G., Lada E., 2008, ApJ, 675, 464Zacharias N., Finch C. T., Girard T. M., Henden A., BartlettJ. L., Monet D. G., Zacharias M. I., 2013, AJ, 145, 44Zhao J. L., He Y. P., 1990, A&A, 237, 54Zwintz K., 2008, ApJ, 673, 1088Zwintz K., Fossati L., Ryabchikova T., Kaiser A., GruberbauerM., Barnes T. G., Baglin A., Chaintreuil S., 2013, A&A, 550,A121This paper has been typeset from a TEX/ L A TEX file prepared bythe author.
APPENDIX A:
In Table A1 we present
UBV I C photometry and coordinatesof variable stars found in NGC 2244 together with some im-portant information about these stars. In Table A2 we present2MASS, UKIDSS, Spitzer and IPHAS infrared photometry ofvariable stars.Phase diagrams of other periodic variables described inSect.3.3 are shown in Appendix A1 and the light curves ofirregular variables variables described in Sect. 3.4. are shownin Appendix A2. c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Table A1.
UBV I C photometry and coordinates of variable stars found in NGC 2244 together with some important informationabout these stars. Star R.Asc. Dec.
V V – I C B – V U – B X (1) H α (2) Cl. (3) α (4) Var. (5)
NIR (6)
Prob. (7)
Other (8)
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name1 6:32:00.61 4:52:40.9 8.530 0.254 0.156 -0.746 a – III -2.61 ECL - 48.6 V578 Mon B0V+B1V2 6:31:33.11 4:50:35.5 12.304 0.587 0.344 -0.177 - BC PS FS -0.25 HAeBe - 87.5 HD 259012B B4/A1Ve3 6:31:29.76 4:54:49.2 12.421 0.453 0.328 -0.256 a BC PS IA I/FS 0.24 HAeBe - 84.7 W74 B7Ve4 6:31:25.39 5:02:08.8 12.836 1.051 0.747 -0.189 - – – — — - 0.0 W62 B35 6:31:30.88 4:58:12.4 12.892 0.439 0.415 0.296 - – III -2.93 DSCT - 27.1 W69 A26 6:31:40.02 5:05:56.8 13.084 1.302 0.987 0.115 - BC (II) (-0.48) HAeBe - 0.0 W106 F3Ve7 6:32:35.43 4:51:58.7 13.535 0.776 0.700 0.181 - Ia III -2.61 MS - 0.0 W264 G28 6:32:30.90 4:47:53.8 13.556 0.937 0.924 0.543 a BC Ia III -2.84 MS - 0.0 W7619 6:31:51.57 4:54:17.5 13.677 0.681 0.519 0.340 - PS IA – 1.06 HAeBe - 92.1 W13110 6:31:41.12 4:56:07.7 14.037 1.332 1.105 0.479 b BC Ib III -2.78 — - 89.7 W12611 6:32:15.85 4:54:30.1 14.287 1.493 1.253 0.665 c BC Ib III -2.56 WTTS - 41.7 W25712 6:32:19.94 4:48:19.2 14.335 1.418 1.183 0.571 a BC III -2.61 — - 85.6 W27213 6:32:24.84 4:57:46.4 14.361 0.997 0.896 0.417 a BC Ia III -2.74 MS - 0.0 W25014 6:32:07.09 4:56:29.9 14.406 1.464 1.255 0.687 c BC Ib III -2.47 WTTS - 91.9 W18715 6:32:31.01 4:50:05.9 14.410 1.247 1.019 0.468 - BC Ib II -0.78 HAeBe* - 89.3 W26916 6:32:28.08 4:54:03.8 14.544 1.287 1.070 0.449 c BC Ib III -2.77 — - 90.2 W140617 6:32:06.52 4:47:55.4 14.690 1.233 1.082 0.751 - Ia II -1.11 HAeBe* P 91.4 V551 Mon18 6:32:06.37 5:02:36.9 15.021 1.027 0.759 0.360 - – III -2.84 DSCT - 62.2 W1689 nm19 6:32:24.42 4:52:22.6 15.325 1.431 1.183 0.609 a BC Ib III -2.71 ECL - 80.6 W240020 6:32:09.98 4:54:23.2 15.396 1.409 1.215 0.604 a BC Ib III -2.73 — - 91.2 W230121 6:32:04.35 4:57:58.2 15.453 1.263 1.038 0.266 b Ib III -2.87 — - 0.0 W150522 6:32:05.41 4:56:59.4 15.788 1.675 1.404 0.908 a BC Ib III -2.70 WTTS F 90.8 W225823 6:32:11.62 4:53:57.0 15.834 1.605 1.338 0.830 a – III -2.73 WTTS* F 17.2 W230824 6:31:47.39 4:53:20.3 15.863 1.572 1.311 0.818 a – III -2.97 — - 91.7 W212125 6:32:02.10 4:48:55.5 15.936 1.595 1.340 0.808 a BC III -2.79 WTTS* F 90.7 W223626 6:32:21.47 4:50:27.4 16.064 1.676 1.336 0.922 a – III -2.78 WTTS* F 91.9 W237927 6:31:57.48 4:55:04.5 16.130 1.522 1.307 0.821 - Ib III -2.54 WTTS F 91.5 W220328 6:31:59.94 4:51:10.0 16.168 1.614 1.369 0.875 c – III -2.58 WTTS* F 91.8 W222029 6:31:30.58 4:58:35.8 16.173 1.040 0.916 0.331 a Ib – — — - 0.0 W2030 nm30 6:31:51.41 4:57:28.6 16.183 1.734 1.387 0.982 a BC Ib III -2.61 WTTS F 91.5 W214931 6:31:48.13 4:53:37.9 16.218 1.695 1.421 0.993 a – III -2.64 WTTS* F 91.7 W212432 6:32:00.31 5:00:42.0 16.231 1.716 1.439 0.979 - BC III -2.77 WTTS* F 90.2 W222233 6:32:11.64 4:50:27.1 16.343 1.533 1.259 0.676 a – III -2.63 WTTS* F 91.5 W230934 6:32:03.37 4:52:35.9 16.374 1.695 1.540 1.029 a – II -1.33 CTTS* F 51.6 W224535 6:32:04.72 4:49:14.8 16.384 1.634 1.390 0.925 b BC III -2.56 WTTS* F 90.0 W225636 6:31:33.44 4:58:26.0 16.475 1.057 0.891 0.233 a Ib – — — - 85.0 W2042 nm37 6:31:28.44 4:54:50.4 16.498 1.559 1.288 0.874 a – – — — F 88.6 W201938 6:32:06.03 4:50:31.2 16.503 1.802 1.497 1.163 b – III -2.71 WTTS* F 90.5 W226739 6:31:56.30 4:54:16.2 16.539 1.827 1.487 1.124 - Ib III -2.74 WTTS F 90.7 W219440 6:32:05.90 4:57:05.4 16.629 1.906 1.527 1.062 b Ib III -2.70 WTTS F 0.4 W226441 6:31:50.56 4:55:53.1 16.630 1.962 1.565 0.890 - Ib III -2.72 WTTS F 89.2 W214142 6:32:00.94 4:51:55.9 16.647 1.846 1.526 1.344 a – II 0.42 CTTS* F 1.5 V549 Mon43 6:32:02.10 4:56:47.2 16.653 1.817 1.421 0.959 a BC III -2.64 WTTS* F 91.3 W223544 6:31:57.30 4:54:51.5 16.674 1.953 1.495 1.016 - BC Ib TD -2.24 WTTS F 88.4 W220045 6:31:43.86 5:02:57.5 16.697 2.032 1.664 0.962 a BC Ia FS* -0.43 CTTS F 91.4 W72546 6:32:30.92 4:50:07.3 16.727 1.605 1.329 0.948 - Ib – (-0.82) — - 0.0 W245747 6:32:15.02 4:52:35.4 16.764 1.762 1.393 0.957 - Ia III -2.11 WTTS F 69.7 W232448 6:31:51.63 4:51:24.0 16.765 2.009 1.554 1.128 a BC III -2.57 ECL F 83.1 W215249 6:31:48.30 4:58:19.8 16.809 2.038 1.395 0.267 b BC II -1.72 CTTS* F 0.0 W212550 6:32:04.54 4:53:25.0 16.892 1.809 1.340 0.796 c PS Ib II -1.53 CTTS* F 78.3 W225451 6:32:13.83 4:49:36.5 16.898 1.759 1.519 1.171 a – III -2.82 WTTS* F 91.3 –52 6:32:05.22 4:48:27.9 16.908 1.255 1.044 0.380 - BC – — — - 85.1 W745 nm53 6:32:21.40 4:54:04.0 16.912 1.555 1.343 0.858 c – – — — F 88.0 W237854 6:32:07.71 5:05:24.3 16.928 1.285 0.993 0.255 - – – — ECL - 0.0 V552 Mon nm55 6:31:25.81 4:58:14.1 16.932 1.816 1.421 0.916 - Ib III -2.86 WTTS F — W201056 6:32:31.59 4:55:25.1 16.974 1.979 1.612 1.083 - BC III -2.43 WTTS* F 82.7 W246957 6:32:23.18 5:00:57.2 16.990 1.772 1.538 0.757 a – III -2.66 WTTS* F 81.7 W239258 6:32:06.70 4:55:30.6 17.011 1.992 1.572 0.870 - BC II -0.71 CTTS* F 21.5 W74659 6:31:32.02 5:05:16.1 17.069 1.521 1.315 0.793 - – – — — F 88.3 –60 6:31:49.26 4:57:01.0 17.074 1.779 1.528 0.571 b BC Ia II -1.20 CTTS F 90.2 W73061 6:31:41.98 4:54:18.2 17.087 1.709 1.379 0.698 b IA II -1.39 CTTS F 89.0 –62 6:31:50.78 4:54:34.7 17.100 1.863 1.462 0.991 a BC Ib III -2.88 WTTS F 91.1 W73263 6:31:40.87 4:59:01.1 17.182 1.203 1.014 0.376 a Ib – — — - 50.0 – nm64 6:32:18.03 4:49:02.0 17.211 1.878 1.535 1.033 a – III -2.60 WTTS* F 89.3 –65 6:32:16.13 4:55:30.0 17.214 2.209 0.937 0.461 - Ia II -0.45 CTTS T 0.0 V555 Mon66 6:31:59.26 5:01:17.2 17.215 2.134 1.646 0.944 c – II -1.58 CTTS* F 89.2 –67 6:31:28.84 4:52:13.3 17.234 1.918 1.488 0.691 a PS IA II -1.26 CTTS F 77.7 W202168 6:31:59.33 5:05:59.9 17.244 1.396 1.184 0.554 - Ib – — — - — – nm69 6:32:17.58 4:53:08.3 17.250 1.830 1.525 0.914 b – II -1.47 CTTS* F 89.7 –70 6:32:20.83 5:04:16.5 17.281 1.834 1.632 0.880 - – II -1.13 CTTS* F 82.6 – c (cid:13) , 1–, 1–
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name1 6:32:00.61 4:52:40.9 8.530 0.254 0.156 -0.746 a – III -2.61 ECL - 48.6 V578 Mon B0V+B1V2 6:31:33.11 4:50:35.5 12.304 0.587 0.344 -0.177 - BC PS FS -0.25 HAeBe - 87.5 HD 259012B B4/A1Ve3 6:31:29.76 4:54:49.2 12.421 0.453 0.328 -0.256 a BC PS IA I/FS 0.24 HAeBe - 84.7 W74 B7Ve4 6:31:25.39 5:02:08.8 12.836 1.051 0.747 -0.189 - – – — — - 0.0 W62 B35 6:31:30.88 4:58:12.4 12.892 0.439 0.415 0.296 - – III -2.93 DSCT - 27.1 W69 A26 6:31:40.02 5:05:56.8 13.084 1.302 0.987 0.115 - BC (II) (-0.48) HAeBe - 0.0 W106 F3Ve7 6:32:35.43 4:51:58.7 13.535 0.776 0.700 0.181 - Ia III -2.61 MS - 0.0 W264 G28 6:32:30.90 4:47:53.8 13.556 0.937 0.924 0.543 a BC Ia III -2.84 MS - 0.0 W7619 6:31:51.57 4:54:17.5 13.677 0.681 0.519 0.340 - PS IA – 1.06 HAeBe - 92.1 W13110 6:31:41.12 4:56:07.7 14.037 1.332 1.105 0.479 b BC Ib III -2.78 — - 89.7 W12611 6:32:15.85 4:54:30.1 14.287 1.493 1.253 0.665 c BC Ib III -2.56 WTTS - 41.7 W25712 6:32:19.94 4:48:19.2 14.335 1.418 1.183 0.571 a BC III -2.61 — - 85.6 W27213 6:32:24.84 4:57:46.4 14.361 0.997 0.896 0.417 a BC Ia III -2.74 MS - 0.0 W25014 6:32:07.09 4:56:29.9 14.406 1.464 1.255 0.687 c BC Ib III -2.47 WTTS - 91.9 W18715 6:32:31.01 4:50:05.9 14.410 1.247 1.019 0.468 - BC Ib II -0.78 HAeBe* - 89.3 W26916 6:32:28.08 4:54:03.8 14.544 1.287 1.070 0.449 c BC Ib III -2.77 — - 90.2 W140617 6:32:06.52 4:47:55.4 14.690 1.233 1.082 0.751 - Ia II -1.11 HAeBe* P 91.4 V551 Mon18 6:32:06.37 5:02:36.9 15.021 1.027 0.759 0.360 - – III -2.84 DSCT - 62.2 W1689 nm19 6:32:24.42 4:52:22.6 15.325 1.431 1.183 0.609 a BC Ib III -2.71 ECL - 80.6 W240020 6:32:09.98 4:54:23.2 15.396 1.409 1.215 0.604 a BC Ib III -2.73 — - 91.2 W230121 6:32:04.35 4:57:58.2 15.453 1.263 1.038 0.266 b Ib III -2.87 — - 0.0 W150522 6:32:05.41 4:56:59.4 15.788 1.675 1.404 0.908 a BC Ib III -2.70 WTTS F 90.8 W225823 6:32:11.62 4:53:57.0 15.834 1.605 1.338 0.830 a – III -2.73 WTTS* F 17.2 W230824 6:31:47.39 4:53:20.3 15.863 1.572 1.311 0.818 a – III -2.97 — - 91.7 W212125 6:32:02.10 4:48:55.5 15.936 1.595 1.340 0.808 a BC III -2.79 WTTS* F 90.7 W223626 6:32:21.47 4:50:27.4 16.064 1.676 1.336 0.922 a – III -2.78 WTTS* F 91.9 W237927 6:31:57.48 4:55:04.5 16.130 1.522 1.307 0.821 - Ib III -2.54 WTTS F 91.5 W220328 6:31:59.94 4:51:10.0 16.168 1.614 1.369 0.875 c – III -2.58 WTTS* F 91.8 W222029 6:31:30.58 4:58:35.8 16.173 1.040 0.916 0.331 a Ib – — — - 0.0 W2030 nm30 6:31:51.41 4:57:28.6 16.183 1.734 1.387 0.982 a BC Ib III -2.61 WTTS F 91.5 W214931 6:31:48.13 4:53:37.9 16.218 1.695 1.421 0.993 a – III -2.64 WTTS* F 91.7 W212432 6:32:00.31 5:00:42.0 16.231 1.716 1.439 0.979 - BC III -2.77 WTTS* F 90.2 W222233 6:32:11.64 4:50:27.1 16.343 1.533 1.259 0.676 a – III -2.63 WTTS* F 91.5 W230934 6:32:03.37 4:52:35.9 16.374 1.695 1.540 1.029 a – II -1.33 CTTS* F 51.6 W224535 6:32:04.72 4:49:14.8 16.384 1.634 1.390 0.925 b BC III -2.56 WTTS* F 90.0 W225636 6:31:33.44 4:58:26.0 16.475 1.057 0.891 0.233 a Ib – — — - 85.0 W2042 nm37 6:31:28.44 4:54:50.4 16.498 1.559 1.288 0.874 a – – — — F 88.6 W201938 6:32:06.03 4:50:31.2 16.503 1.802 1.497 1.163 b – III -2.71 WTTS* F 90.5 W226739 6:31:56.30 4:54:16.2 16.539 1.827 1.487 1.124 - Ib III -2.74 WTTS F 90.7 W219440 6:32:05.90 4:57:05.4 16.629 1.906 1.527 1.062 b Ib III -2.70 WTTS F 0.4 W226441 6:31:50.56 4:55:53.1 16.630 1.962 1.565 0.890 - Ib III -2.72 WTTS F 89.2 W214142 6:32:00.94 4:51:55.9 16.647 1.846 1.526 1.344 a – II 0.42 CTTS* F 1.5 V549 Mon43 6:32:02.10 4:56:47.2 16.653 1.817 1.421 0.959 a BC III -2.64 WTTS* F 91.3 W223544 6:31:57.30 4:54:51.5 16.674 1.953 1.495 1.016 - BC Ib TD -2.24 WTTS F 88.4 W220045 6:31:43.86 5:02:57.5 16.697 2.032 1.664 0.962 a BC Ia FS* -0.43 CTTS F 91.4 W72546 6:32:30.92 4:50:07.3 16.727 1.605 1.329 0.948 - Ib – (-0.82) — - 0.0 W245747 6:32:15.02 4:52:35.4 16.764 1.762 1.393 0.957 - Ia III -2.11 WTTS F 69.7 W232448 6:31:51.63 4:51:24.0 16.765 2.009 1.554 1.128 a BC III -2.57 ECL F 83.1 W215249 6:31:48.30 4:58:19.8 16.809 2.038 1.395 0.267 b BC II -1.72 CTTS* F 0.0 W212550 6:32:04.54 4:53:25.0 16.892 1.809 1.340 0.796 c PS Ib II -1.53 CTTS* F 78.3 W225451 6:32:13.83 4:49:36.5 16.898 1.759 1.519 1.171 a – III -2.82 WTTS* F 91.3 –52 6:32:05.22 4:48:27.9 16.908 1.255 1.044 0.380 - BC – — — - 85.1 W745 nm53 6:32:21.40 4:54:04.0 16.912 1.555 1.343 0.858 c – – — — F 88.0 W237854 6:32:07.71 5:05:24.3 16.928 1.285 0.993 0.255 - – – — ECL - 0.0 V552 Mon nm55 6:31:25.81 4:58:14.1 16.932 1.816 1.421 0.916 - Ib III -2.86 WTTS F — W201056 6:32:31.59 4:55:25.1 16.974 1.979 1.612 1.083 - BC III -2.43 WTTS* F 82.7 W246957 6:32:23.18 5:00:57.2 16.990 1.772 1.538 0.757 a – III -2.66 WTTS* F 81.7 W239258 6:32:06.70 4:55:30.6 17.011 1.992 1.572 0.870 - BC II -0.71 CTTS* F 21.5 W74659 6:31:32.02 5:05:16.1 17.069 1.521 1.315 0.793 - – – — — F 88.3 –60 6:31:49.26 4:57:01.0 17.074 1.779 1.528 0.571 b BC Ia II -1.20 CTTS F 90.2 W73061 6:31:41.98 4:54:18.2 17.087 1.709 1.379 0.698 b IA II -1.39 CTTS F 89.0 –62 6:31:50.78 4:54:34.7 17.100 1.863 1.462 0.991 a BC Ib III -2.88 WTTS F 91.1 W73263 6:31:40.87 4:59:01.1 17.182 1.203 1.014 0.376 a Ib – — — - 50.0 – nm64 6:32:18.03 4:49:02.0 17.211 1.878 1.535 1.033 a – III -2.60 WTTS* F 89.3 –65 6:32:16.13 4:55:30.0 17.214 2.209 0.937 0.461 - Ia II -0.45 CTTS T 0.0 V555 Mon66 6:31:59.26 5:01:17.2 17.215 2.134 1.646 0.944 c – II -1.58 CTTS* F 89.2 –67 6:31:28.84 4:52:13.3 17.234 1.918 1.488 0.691 a PS IA II -1.26 CTTS F 77.7 W202168 6:31:59.33 5:05:59.9 17.244 1.396 1.184 0.554 - Ib – — — - — – nm69 6:32:17.58 4:53:08.3 17.250 1.830 1.525 0.914 b – II -1.47 CTTS* F 89.7 –70 6:32:20.83 5:04:16.5 17.281 1.834 1.632 0.880 - – II -1.13 CTTS* F 82.6 – c (cid:13) , 1–, 1– ?? G. Michalska
Table A1 – continued Star R.Asc. Dec.
V V – I C B – V U – B X (1) H α (2) Cl. (3) α (4) Var. (5)
NIR (6)
Prob. (7)
Other (8)
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name71 6:32:14.74 4:50:23.7 17.314 2.036 1.677 — a – III -2.73 WTTS* F 88.5 –72 6:31:34.31 5:04:16.0 17.349 1.131 0.854 0.267 - – – — ECL - 0.0 – nm73 6:32:05.93 4:57:27.7 17.350 2.077 1.493 0.686 a Ia II -0.73 CTTS F 29.1 –74 6:31:57.34 4:53:42.3 17.383 1.874 1.465 — a – II -1.85 — F 89.7 –75 6:31:43.92 5:02:38.9 17.404 1.410 1.056 0.454 - – – — DSCT - 1.1 – nm76 6:32:07.82 4:52:28.5 17.407 1.843 1.439 0.565 c IA II -1.16 CTTS F 88.9 –77 6:31:51.48 4:51:32.0 17.408 2.216 1.727 0.724 a Ib II -1.78 CTTS* F — –78 6:32:20.34 4:58:41.8 17.413 2.016 1.617 0.639 a Ib III -2.79 WTTS F 91.0 –79 6:32:08.02 4:50:33.6 17.418 2.005 1.574 0.734 a – III -2.67 WTTS* F 89.6 –80 6:32:04.69 4:47:45.6 17.442 1.922 1.563 0.710 - Ib II -1.25 CTTS* F 48.4 –81 6:31:57.19 4:50:12.0 17.458 2.125 1.636 0.391 a – III -2.77 WTTS* F — –82 6:31:51.64 4:55:05.3 17.460 1.902 1.610 0.749 - Ib II -1.62 CTTS* F 88.7 V547 Mon83 6:31:27.85 4:50:03.0 17.515 1.909 0.998 — - IA II -1.04 CTTS T 36.8 V544 Mon84 6:32:16.67 4:49:38.2 17.523 1.912 1.564 0.843 c – FS* -0.61 CTTS* F 87.5 –85 6:32:20.25 4:57:55.8 17.527 1.987 1.496 0.952 c – III -2.31 WTTS* F 80.0 –86 6:32:05.44 4:57:30.1 17.532 2.045 1.658 — b – III -2.91 — F 90.8 –87 6:31:59.12 4:55:26.0 17.552 2.090 1.213 — - Ib II -1.80 CTTS* F 89.4 –88 6:31:41.02 4:54:47.9 17.567 1.919 1.451 0.559 b BC IA II -1.15 CTTS F 86.1 W72489 6:32:23.11 4:49:43.2 17.585 2.233 1.873 — a BC II -1.42 CTTS* F 90.6 W75690 6:31:50.44 4:56:38.4 17.603 2.081 1.425 0.563 c Ib III -2.12 WTTS F 0.4 –91 6:32:22.77 5:00:31.9 17.609 1.903 1.591 0.690 b – III -2.73 WTTS* F 86.3 –92 6:31:30.03 5:00:45.6 17.625 1.519 1.116 0.731 - – – — DSCT - 0.0 – nm93 6:32:10.65 4:51:32.7 17.634 1.949 1.593 — a – III -2.78 WTTS* F 88.8 –94 6:31:21.43 4:54:05.8 17.637 2.055 1.602 — - – – — — F 85.0 –95 6:31:43.89 5:03:56.5 17.669 1.775 1.437 0.733 c BC – — — F 15.3 W72696 6:32:23.41 4:52:39.2 17.690 2.164 1.596 0.527 - Ib II -1.66 CTTS* F 85.5 –97 6:31:44.47 5:03:42.2 17.693 1.962 1.508 0.700 a Ib III -2.63 WTTS F 57.3 –98 6:31:36.42 4:53:13.9 17.713 2.147 1.497 0.291 a BC Ia II -0.87 CTTS F 53.3 W72199 6:32:04.66 4:54:51.5 17.727 2.134 1.692 — c Ia II -1.71 CTTS F 80.2 –100 6:31:46.07 4:54:30.8 17.744 2.098 1.559 0.859 b – III -2.68 WTTS* F 83.3 –101 6:31:50.26 5:00:07.8 17.749 1.999 1.597 0.710 c – TD -1.94 WTTS F 78.5 –102 6:31:20.86 5:04:08.7 17.752 1.989 1.548 — - Ib II -1.52 CTTS* F 0.1 –103 6:31:38.78 4:55:24.9 17.755 2.113 1.658 — a Ib III -2.60 WTTS F 86.0 –104 6:31:50.43 4:51:50.1 17.765 1.930 1.362 — a IA II -1.96 CTTS F 73.9 –105 6:32:20.79 4:52:58.2 17.770 2.035 1.605 — b BC Ib III -2.72 WTTS F — W754106 6:32:01.17 4:55:27.3 17.775 1.951 1.613 — - Ib III -2.09 WTTS F 84.5 –107 6:32:14.81 4:48:55.4 17.788 1.951 1.499 — b – III -2.73 WTTS* F 90.3 –108 6:31:47.56 4:49:07.7 17.795 2.003 1.586 — a BC III -2.93 WTTS* F 85.3 W729109 6:31:55.25 4:53:29.9 17.805 1.997 1.544 0.688 - – III -2.99 WTTS* F 78.4 W735110 6:32:10.89 4:57:06.2 17.854 1.914 1.663 — c Ib III -2.62 WTTS F — –111 6:31:55.82 4:51:27.3 17.858 2.084 1.601 — c – – — — F 77.6 –112 6:31:55.60 4:55:17.3 17.868 2.006 1.419 — b Ib III -1.85 WTTS F 87.2 –113 6:31:45.38 4:59:02.4 17.885 2.073 1.609 — a – III -2.55 WTTS* F 69.9 –114 6:32:23.85 5:06:13.5 17.918 1.224 1.325 0.522 - – – — — - — – nm115 6:31:57.61 5:02:29.1 17.938 2.095 1.570 — b Ib II -1.41 CTTS* F 42.4 –116 6:31:36.87 4:51:04.3 17.942 2.255 1.620 — b – FS -0.18 CTTS F 0.0 W2062117 6:32:29.24 5:05:15.9 17.945 1.924 1.584 — - Ia – — — F 90.2 –118 6:31:27.66 4:54:02.8 17.957 2.365 1.681 — a – III -2.47 WTTS* F 8.0 –119 6:32:00.54 5:05:33.5 18.032 1.943 1.563 — - – – — — - 71.7 W2225120 6:32:25.13 4:55:14.4 18.046 1.960 1.574 — a – II -1.58 CTTS* F 88.0 –121 6:31:55.52 4:53:46.9 18.072 2.096 1.619 — - Ib II -1.05 CTTS* F 89.2 –122 6:31:48.72 4:55:21.0 18.087 2.024 1.678 — - – – — — F 86.8 –123 6:32:00.48 4:59:46.9 18.088 2.018 1.594 — a – III -2.50 WTTS* F — –124 6:31:55.03 4:53:20.8 18.094 2.205 1.709 — - – III -2.62 WTTS* F 87.6 –125 6:32:09.92 4:50:15.0 18.110 2.039 1.677 — c – – — — F 83.9 –126 6:32:07.55 4:56:15.3 18.119 2.244 1.691 — a – III -2.68 WTTS* F 57.4 –127 6:32:10.92 4:55:02.6 18.127 1.940 1.579 — - Ia II -1.28 CTTS F 84.7 –128 6:32:27.18 4:52:41.9 18.127 1.864 1.493 — - – – — — F 85.0 –129 6:31:47.44 4:53:31.5 18.133 2.244 1.699 — a – – — — F 0.0 –130 6:31:47.70 4:56:49.8 18.141 2.219 1.686 — a BC III -2.77 WTTS* F 90.3 W728131 6:32:05.08 4:55:46.9 18.160 1.927 1.478 — c Ib II -0.94 CTTS T 89.0 –132 6:31:56.93 4:53:02.0 18.168 2.066 1.691 — b – II -1.49 CTTS* F 80.9 –133 6:32:01.84 4:53:38.6 18.179 2.024 1.472 — a BC IA TD -1.24 CTTS F 78.8 W740134 6:31:36.77 4:53:10.0 18.182 2.156 1.593 — a – II -0.82 CTTS* F 76.6 –135 6:31:54.60 4:59:41.7 18.182 1.916 1.491 — a – – — — F 89.2 –136 6:31:57.09 4:54:36.4 18.184 2.161 1.650 — - – III -2.72 WTTS* F 82.4 –137 6:32:08.29 4:50:56.5 18.209 2.126 1.756 — a – – — — F 81.1 –138 6:32:02.93 4:58:54.0 18.226 2.218 1.617 — a Ib III -2.75 WTTS F 88.3 –139 6:31:52.01 4:54:08.4 18.237 2.032 1.660 — a BC Ib – — — F 88.1 W734140 6:32:07.67 4:54:33.7 18.251 2.132 1.606 — b – TD -1.17 CTTS* F 67.7 – c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Table A1 – continued Star R.Asc. Dec.
V V – I C B – V U – B X (1) H α (2) Cl. (3) α (4) Var. (5)
NIR (6)
Prob. (7)
Other (8)
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name141 6:31:59.63 4:52:16.8 18.264 2.245 — — a Ib III -2.51 WTTS F 88.3 –142 6:31:39.62 4:59:45.1 18.270 2.454 1.640 — a Ia II -1.53 CTTS F 74.9 –143 6:31:49.81 4:49:06.8 18.277 2.268 1.611 — - Ib III -2.71 WTTS F — –144 6:31:59.70 4:55:36.0 18.280 2.225 — — - – III -2.66 WTTS* F 89.1 –145 6:31:48.05 4:50:48.3 18.287 2.343 1.389 — - IA II -0.54 CTTS F 0.0 –146 6:31:43.57 4:59:49.1 18.310 2.238 1.632 — b – – — — F 57.7 –147 6:31:30.24 4:51:48.5 18.318 2.141 1.506 — - Ia II -1.50 CTTS F 88.7 –148 6:31:37.22 4:56:57.3 18.329 2.075 1.620 — - – – — — F 87.8 –149 6:32:01.02 4:57:31.8 18.379 2.153 1.457 — a Ia II -1.22 CTTS F 89.0 –150 6:31:47.45 4:58:32.9 18.387 2.133 — — a – III -2.58 WTTS* F 89.1 –151 6:32:15.12 4:59:57.5 18.390 2.248 1.586 — - – III -2.44 — F 42.2 –152 6:31:47.59 4:50:52.9 18.408 2.393 1.545 — c Ib II -1.19 CTTS* F 81.7 –153 6:32:25.76 4:58:23.3 18.443 2.448 — — - – – — — F 89.7 –154 6:32:22.27 4:47:14.1 18.449 2.399 1.015 — - Ia III -2.77 WTTS F 85.7 –155 6:31:39.56 4:53:38.6 18.462 2.120 1.331 — c IA III -1.22 CTTS* F 78.9 –156 6:32:09.33 4:52:41.4 18.481 2.451 — — c Ia III -2.85 WTTS F 79.2 –157 6:31:52.56 4:58:17.4 18.498 2.231 — — a Ib III -2.70 WTTS F 88.0 –158 6:31:56.79 4:53:51.1 18.498 2.126 — — - – TD -1.33 CTTS* F 80.7 –159 6:31:46.10 4:57:50.8 18.540 2.122 — — a – – — — F 89.8 –160 6:31:32.09 4:57:38.8 18.555 2.172 — — a Ib TD -1.57 CTTS* F 83.6 –161 6:31:45.11 4:51:26.2 18.562 2.190 — — - BC – — — F 65.7 W727162 6:31:58.14 4:48:29.9 18.574 2.255 — — a – – — — F 74.5 –163 6:31:30.95 4:48:48.4 18.579 2.353 — — - Ib II -0.88 CTTS* F 86.7 –164 6:32:12.21 4:56:32.8 18.602 2.140 — — - – – — — F 77.4 –165 6:31:39.18 4:49:59.5 18.628 1.894 1.038 — b IA II -1.06 CTTS F 84.8 –166 6:31:48.89 4:56:09.3 18.631 2.171 — — - Ib II -1.12 CTTS* F 88.0 –167 6:31:39.31 4:54:01.0 18.648 2.401 — — a – – — — F 3.1 –168 6:32:30.05 4:57:26.4 18.651 2.065 — — - Ia – — — F 48.5 –169 6:31:41.98 4:54:16.3 18.676 2.255 — — a IA – — — F 74.2 –170 6:31:24.42 4:53:05.5 18.695 1.667 1.188 — - Ib – — ECL F 0.0 – nm171 6:31:49.53 4:52:00.0 18.707 1.951 — — a – – — — F 42.3 –172 6:31:48.31 4:52:38.8 18.760 2.219 — — - Ib II -1.48 CTTS* F 85.8 –173 6:31:56.53 4:54:28.4 18.771 2.317 — — - – III -2.49 WTTS* F 86.9 –174 6:31:41.13 4:55:51.5 18.777 2.242 — — a – – — — F 83.3 –175 6:32:01.50 4:54:45.1 18.779 2.274 — — a Ib II -0.86 CTTS* F 86.3 –176 6:32:01.11 4:54:49.8 18.797 2.538 — — a – – — — F 86.1 –177 6:32:06.49 4:48:46.6 18.803 2.367 — — a – III -2.37 WTTS* F 40.0 –178 6:31:41.58 4:59:40.5 18.814 2.146 — — a – – — — F 79.6 –179 6:32:12.34 4:57:21.9 18.853 2.368 — — a Ib II -1.30 CTTS* F 84.3 –180 6:32:26.57 4:52:38.3 18.865 2.122 — — - IA II -0.92 CTTS F 82.1 –181 6:31:41.90 4:50:46.1 18.868 2.288 — — c Ia II -1.93 CTTS F 83.3 –182 6:32:12.86 4:58:38.1 18.875 2.384 — — a – III -2.60 WTTS* F 70.0 –183 6:31:43.35 4:57:24.9 18.934 2.264 — — a Ib II -1.68 CTTS* F 80.4 –184 6:31:53.78 4:48:47.1 18.941 2.696 — — - Ib III -2.78 WTTS F 60.0 –185 6:32:12.18 5:01:39.8 18.953 2.028 — — a – II -1.34 CTTS* F — –186 6:31:44.92 4:56:00.2 18.963 2.617 — — - Ia II -1.34 CTTS F 0.0 –187 6:31:47.79 4:52:23.9 18.973 2.326 — — - Ia II -0.61 CTTS F 66.8 –188 6:31:50.35 4:57:39.0 18.994 2.493 — — a Ib – — — F 80.5 –189 6:31:18.44 4:54:40.2 19.002 2.196 — — - Ia – — — F 85.8 –190 6:32:04.47 4:58:26.2 19.014 2.276 — — c Ia III -1.96 WTTS F 86.1 –191 6:32:16.16 4:59:20.1 19.060 2.420 — — c – II -1.06 CTTS* F 87.1 –192 6:31:56.87 4:55:14.7 19.100 2.579 — — - Ib – — — F 83.9 –193 6:31:54.93 4:51:36.1 19.121 2.327 — — - IA – — — F 80.2 –194 6:32:30.12 4:55:22.2 19.187 2.431 — — - IA II -1.65 CTTS F 0.3 –195 6:31:59.30 4:51:37.6 19.202 2.354 — — a – – — — F — –196 6:31:39.88 4:56:39.2 19.224 2.363 — — - IA III -2.32 WTTS F 53.3 –197 6:32:03.08 5:01:34.9 19.225 2.293 — — a IA II -0.98 CTTS F 63.2 –198 6:32:06.99 4:48:03.8 19.227 2.390 — — b Ib – — — F 82.0 –199 6:31:19.48 4:53:09.7 19.242 2.588 — — - Ib – — — F 52.1 –200 6:31:58.92 4:57:43.2 19.242 2.351 — — - Ib II -1.28 CTTS* F 82.5 –201 6:32:01.51 4:55:02.2 19.251 2.359 — — b Ib – — — F 86.1 –202 6:31:42.59 4:52:56.2 19.256 2.743 — — a Ia II -0.81 CTTS F 58.1 –203 6:32:27.50 4:52:51.3 19.272 2.489 — — c IA II -1.42 CTTS F — –204 6:31:58.89 4:58:11.1 19.299 2.360 — — - IA II -0.60 CTTS F 78.2 –205 6:32:20.34 4:53:20.7 19.368 1.623 — — - Ia – — ECL F 33.6 – nm206 6:32:05.07 4:52:26.7 19.391 2.566 — — b Ia TD -1.99 WTTS F 44.7 –207 6:32:35.69 4:47:46.0 19.402 2.592 — — - – FS -0.31 CTTS* F 0.7 –208 6:31:30.72 4:52:15.0 19.418 2.384 — — c – II -1.24 CTTS* F 87.6 –209 6:31:51.56 4:47:28.0 19.453 2.416 — — - IA II -0.52 CTTS F 78.5 –210 6:31:52.21 4:52:40.0 19.553 2.443 — — a Ia II -1.10 CTTS F 22.4 – c (cid:13) , 1–, 1–
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name141 6:31:59.63 4:52:16.8 18.264 2.245 — — a Ib III -2.51 WTTS F 88.3 –142 6:31:39.62 4:59:45.1 18.270 2.454 1.640 — a Ia II -1.53 CTTS F 74.9 –143 6:31:49.81 4:49:06.8 18.277 2.268 1.611 — - Ib III -2.71 WTTS F — –144 6:31:59.70 4:55:36.0 18.280 2.225 — — - – III -2.66 WTTS* F 89.1 –145 6:31:48.05 4:50:48.3 18.287 2.343 1.389 — - IA II -0.54 CTTS F 0.0 –146 6:31:43.57 4:59:49.1 18.310 2.238 1.632 — b – – — — F 57.7 –147 6:31:30.24 4:51:48.5 18.318 2.141 1.506 — - Ia II -1.50 CTTS F 88.7 –148 6:31:37.22 4:56:57.3 18.329 2.075 1.620 — - – – — — F 87.8 –149 6:32:01.02 4:57:31.8 18.379 2.153 1.457 — a Ia II -1.22 CTTS F 89.0 –150 6:31:47.45 4:58:32.9 18.387 2.133 — — a – III -2.58 WTTS* F 89.1 –151 6:32:15.12 4:59:57.5 18.390 2.248 1.586 — - – III -2.44 — F 42.2 –152 6:31:47.59 4:50:52.9 18.408 2.393 1.545 — c Ib II -1.19 CTTS* F 81.7 –153 6:32:25.76 4:58:23.3 18.443 2.448 — — - – – — — F 89.7 –154 6:32:22.27 4:47:14.1 18.449 2.399 1.015 — - Ia III -2.77 WTTS F 85.7 –155 6:31:39.56 4:53:38.6 18.462 2.120 1.331 — c IA III -1.22 CTTS* F 78.9 –156 6:32:09.33 4:52:41.4 18.481 2.451 — — c Ia III -2.85 WTTS F 79.2 –157 6:31:52.56 4:58:17.4 18.498 2.231 — — a Ib III -2.70 WTTS F 88.0 –158 6:31:56.79 4:53:51.1 18.498 2.126 — — - – TD -1.33 CTTS* F 80.7 –159 6:31:46.10 4:57:50.8 18.540 2.122 — — a – – — — F 89.8 –160 6:31:32.09 4:57:38.8 18.555 2.172 — — a Ib TD -1.57 CTTS* F 83.6 –161 6:31:45.11 4:51:26.2 18.562 2.190 — — - BC – — — F 65.7 W727162 6:31:58.14 4:48:29.9 18.574 2.255 — — a – – — — F 74.5 –163 6:31:30.95 4:48:48.4 18.579 2.353 — — - Ib II -0.88 CTTS* F 86.7 –164 6:32:12.21 4:56:32.8 18.602 2.140 — — - – – — — F 77.4 –165 6:31:39.18 4:49:59.5 18.628 1.894 1.038 — b IA II -1.06 CTTS F 84.8 –166 6:31:48.89 4:56:09.3 18.631 2.171 — — - Ib II -1.12 CTTS* F 88.0 –167 6:31:39.31 4:54:01.0 18.648 2.401 — — a – – — — F 3.1 –168 6:32:30.05 4:57:26.4 18.651 2.065 — — - Ia – — — F 48.5 –169 6:31:41.98 4:54:16.3 18.676 2.255 — — a IA – — — F 74.2 –170 6:31:24.42 4:53:05.5 18.695 1.667 1.188 — - Ib – — ECL F 0.0 – nm171 6:31:49.53 4:52:00.0 18.707 1.951 — — a – – — — F 42.3 –172 6:31:48.31 4:52:38.8 18.760 2.219 — — - Ib II -1.48 CTTS* F 85.8 –173 6:31:56.53 4:54:28.4 18.771 2.317 — — - – III -2.49 WTTS* F 86.9 –174 6:31:41.13 4:55:51.5 18.777 2.242 — — a – – — — F 83.3 –175 6:32:01.50 4:54:45.1 18.779 2.274 — — a Ib II -0.86 CTTS* F 86.3 –176 6:32:01.11 4:54:49.8 18.797 2.538 — — a – – — — F 86.1 –177 6:32:06.49 4:48:46.6 18.803 2.367 — — a – III -2.37 WTTS* F 40.0 –178 6:31:41.58 4:59:40.5 18.814 2.146 — — a – – — — F 79.6 –179 6:32:12.34 4:57:21.9 18.853 2.368 — — a Ib II -1.30 CTTS* F 84.3 –180 6:32:26.57 4:52:38.3 18.865 2.122 — — - IA II -0.92 CTTS F 82.1 –181 6:31:41.90 4:50:46.1 18.868 2.288 — — c Ia II -1.93 CTTS F 83.3 –182 6:32:12.86 4:58:38.1 18.875 2.384 — — a – III -2.60 WTTS* F 70.0 –183 6:31:43.35 4:57:24.9 18.934 2.264 — — a Ib II -1.68 CTTS* F 80.4 –184 6:31:53.78 4:48:47.1 18.941 2.696 — — - Ib III -2.78 WTTS F 60.0 –185 6:32:12.18 5:01:39.8 18.953 2.028 — — a – II -1.34 CTTS* F — –186 6:31:44.92 4:56:00.2 18.963 2.617 — — - Ia II -1.34 CTTS F 0.0 –187 6:31:47.79 4:52:23.9 18.973 2.326 — — - Ia II -0.61 CTTS F 66.8 –188 6:31:50.35 4:57:39.0 18.994 2.493 — — a Ib – — — F 80.5 –189 6:31:18.44 4:54:40.2 19.002 2.196 — — - Ia – — — F 85.8 –190 6:32:04.47 4:58:26.2 19.014 2.276 — — c Ia III -1.96 WTTS F 86.1 –191 6:32:16.16 4:59:20.1 19.060 2.420 — — c – II -1.06 CTTS* F 87.1 –192 6:31:56.87 4:55:14.7 19.100 2.579 — — - Ib – — — F 83.9 –193 6:31:54.93 4:51:36.1 19.121 2.327 — — - IA – — — F 80.2 –194 6:32:30.12 4:55:22.2 19.187 2.431 — — - IA II -1.65 CTTS F 0.3 –195 6:31:59.30 4:51:37.6 19.202 2.354 — — a – – — — F — –196 6:31:39.88 4:56:39.2 19.224 2.363 — — - IA III -2.32 WTTS F 53.3 –197 6:32:03.08 5:01:34.9 19.225 2.293 — — a IA II -0.98 CTTS F 63.2 –198 6:32:06.99 4:48:03.8 19.227 2.390 — — b Ib – — — F 82.0 –199 6:31:19.48 4:53:09.7 19.242 2.588 — — - Ib – — — F 52.1 –200 6:31:58.92 4:57:43.2 19.242 2.351 — — - Ib II -1.28 CTTS* F 82.5 –201 6:32:01.51 4:55:02.2 19.251 2.359 — — b Ib – — — F 86.1 –202 6:31:42.59 4:52:56.2 19.256 2.743 — — a Ia II -0.81 CTTS F 58.1 –203 6:32:27.50 4:52:51.3 19.272 2.489 — — c IA II -1.42 CTTS F — –204 6:31:58.89 4:58:11.1 19.299 2.360 — — - IA II -0.60 CTTS F 78.2 –205 6:32:20.34 4:53:20.7 19.368 1.623 — — - Ia – — ECL F 33.6 – nm206 6:32:05.07 4:52:26.7 19.391 2.566 — — b Ia TD -1.99 WTTS F 44.7 –207 6:32:35.69 4:47:46.0 19.402 2.592 — — - – FS -0.31 CTTS* F 0.7 –208 6:31:30.72 4:52:15.0 19.418 2.384 — — c – II -1.24 CTTS* F 87.6 –209 6:31:51.56 4:47:28.0 19.453 2.416 — — - IA II -0.52 CTTS F 78.5 –210 6:31:52.21 4:52:40.0 19.553 2.443 — — a Ia II -1.10 CTTS F 22.4 – c (cid:13) , 1–, 1– ?? G. Michalska
Table A1 – continued Star R.Asc. Dec.
V V – I C B – V U – B X (1) H α (2) Cl. (3) α (4) Var. (5)
NIR (6)
Prob. (7)
Other (8)
Notes (9) (2000.0) (2000.0) mag mag mag mag type reg. [% ] name211 6:31:32.87 4:59:49.5 19.590 2.092 — — a – II -1.33 CTTS T 86.9 – nm212 6:32:24.01 4:56:59.3 19.593 2.594 — — c IA II -1.31 CTTS F 56.8 –213 6:32:31.92 4:51:09.0 19.615 2.336 — — - Ia II -1.60 CTTS F 12.7 –214 6:32:22.70 4:58:08.4 19.617 2.586 — — a IA II -1.28 CTTS F — –215 6:31:29.84 4:51:10.7 19.645 2.604 — — a IA II -1.04 CTTS T — –216 6:31:25.46 4:49:31.0 19.648 2.426 — — c Ia II -1.19 CTTS F 67.8 –217 6:31:47.36 4:49:43.6 19.699 2.370 — — - Ib – — — F 60.3 –218 6:32:10.37 4:52:05.9 19.703 2.534 — — - Ia II -1.19 CTTS F 65.4 –219 6:31:59.36 4:49:55.0 19.784 2.581 — — b Ia II -1.34 CTTS F 72.2 –220 6:31:58.73 4:53:46.9 19.880 2.205 — — - Ia II -1.84 CTTS F 20.8 – nm221 6:31:29.41 4:50:34.9 19.881 2.516 — — a – – — — F 75.0 –222 6:32:31.50 4:54:53.3 19.932 2.330 — — - IA III -2.03 WTTS T 74.3 –223 6:32:32.66 4:57:01.1 19.976 2.685 — — - Ia II -1.28 CTTS F 75.7 –224 6:31:36.59 5:05:15.2 19.984 3.013 — — - IA (II) (-0.54) CTTS F 71.6 –225 6:32:08.95 5:01:51.3 19.984 2.311 — — - – – (-1.49) — F 69.3 –226 6:31:57.58 4:53:39.0 20.002 2.617 — — a Ib II -0.82 CTTS* F 25.9 –227 6:31:56.58 4:59:51.6 20.007 2.635 — — b – – — — F 57.8 –228 6:32:23.92 4:54:21.0 20.077 2.405 — — - IA III -1.26 CTTS* F 7.4 –229 6:31:43.36 4:54:23.0 20.131 2.083 — — - Ia II -1.74 CTTS F 35.8 – nm230 6:31:32.48 5:06:05.5 20.178 2.972 — — - IA (II) (-0.93) CTTS F 75.0 –231 6:31:41.05 4:54:19.9 20.193 2.779 — — b Ib II -0.94 CTTS T 0.0 –232 6:31:58.10 4:54:15.0 20.199 2.206 — — - – II -1.00 CTTS* F 0.0 – nm233 6:31:48.54 5:04:07.2 20.212 2.696 — — - Ia III -1.55 CTTS* F 53.7 –234 6:31:55.47 5:00:54.2 20.242 2.480 — — - IA II -1.47 CTTS - 75.3 –235 6:31:59.69 5:06:27.2 20.252 2.705 — — - Ib – — — F 46.4 –236 6:32:30.20 4:54:01.3 20.297 2.306 — — - – II -1.19 CTTS* T 19.0 –237 6:31:49.00 4:55:47.0 20.302 2.731 — — a – II -1.29 CTTS* F 55.7 –238 6:32:03.65 4:59:52.2 20.396 2.589 — — a – II -1.32 CTTS* F 43.9 –239 6:31:38.34 5:02:56.6 20.399 2.821 — — - Ia II -1.22 CTTS F 63.4 –240 6:32:19.28 4:56:29.6 20.422 2.157 — — - IA – — — F 35.3 –241 6:32:07.17 4:55:14.5 20.472 2.486 — — - – II -0.95 CTTS* F 39.5 –242 6:31:28.41 4:50:35.2 20.495 2.475 — — - – II -0.83 CTTS* T — –243 6:32:11.98 5:00:31.1 20.496 2.166 — — a Ia I 0.98 CTTS F 43.9 –244 6:32:19.98 4:57:48.5 20.630 2.393 — — - – II -1.65 CTTS* F — –245 6:32:28.81 4:52:56.1 20.751 2.090 — — - – II -1.63 CTTS* F — – (1) a, b, c – X-ray variability from Wang et al. (2008):a = no evidence for variability;b = possibly variable;c = definitely variable. (2) H α emission:IA – stars with H α emission above the empirical threshold in IPHAS ( r (cid:48) − Hα ) vs. ( r (cid:48) − i (cid:48) ) colour-colour diagram (see Sect. 6.1);Ia – stars with photometric EW H α > ˚A based on IPHAS photometry (see Sect. 6.1);Ib – stars with photometric EW H α between 0 and 10 ˚A based on IPHAS photometry (see Sect. 6.1);BC – stars with H α excess from Bergh¨ofer & Christian (2002);PS – stars with H α excess from Park & Sung (2002). (3) Classification based on
Spitzer photometry (see Sect. 5):I – Class I objects;II – Class II objects;TD – transition disks objects;FS – flat spectrum objects with α index between -0.3 and 0.3;FS (cid:63) – flat spectrum objects with ( K − [24]) colour between 6.75 and 8.31 (Sect. 5.1.3);III – field stars and/or diskless YSOs (Class III);(II) – Class II objects found based on WISE photometry in case of lack Spitzer photometry (see Sect. 5.3). (4)
Spectral index α = d log( λF λ ) /d log( λ ) calculated from the slope of the linear fit to the fluxes between the K band and the IRAC [8] µ m band (Lada et al. 2006): α > . : Class I YSOs; − . < α < . : flat spectrum objects; − . < α < − . : Class II YSOs; α < − . : Class III objects. α in brackets – spectral index found based on WISE photometry in case of lack Spitzer photometry (see Sect. 5.3). (5)
Variability type:CTTS – the best candidates for CTTSs: Class II stars with photometric EW H α >
10 ˚A lying above CTTS line in ( J − H ) vs. ( H − K ) colour-colour diagram (Fig. 21);CTTS (cid:63) – additional candidates for CTTSs: objects lying above CTTS line in ( J − H ) vs. ( H − K ) colour-colour diagram and having spectra lindex α > − . (Class III stars with photometric EW H α >
10 ˚A and Class II objects with photometric EW H α <
10 ˚A or without EW H α );WTTS – candidates for WTTSs: objects lying above CTTS line with spectral index α < − . (Class II with photometric EW H α <
10 ˚Aor Class III objects with photometric 0 < EW H α <
10 ˚A);WTTS (cid:63) – remaining objects lying above CTTS line. (6)
The area in ( J − H ) vs. ( H − K ) colour-colour diagram in Fig.21. (7) Membership probability determined in Sect.4. (8 Other name:the other name of the star (from GCVS, HD catalogues or WEBDA number). The names from UKIDSS-DR6 catalogue (Lucas et al. 2008) are shown in Table A2 (9)
Notes:nm – non-member – the membership determined from V vs. ( V − I C ) colour-magnitude diagram. c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Table A2.
Star Name
J H K S J H K [3 .
6] [4 .
5] [5 .
8] [8 .
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag1 J063200.60+045240.9 8.152 8.125 8.120 10.825 11.668 9.523 8.376 8.311 8.197 8.184 — — — —2 J063133.11+045035.4 10.770 9.942 9.115 10.715 10.823 9.641 7.713 7.136 6.435 5.484 2.707 — — —3 J063129.76+045449.1 11.449 10.887 9.690 11.371 11.148 9.843 7.422 6.753 6.061 4.740 1.783 12.22 11.89 11.574 J063125.42+050209.3 10.977 10.711 10.544 10.913 11.005 10.560 — — — — — — — —5 J063130.87+045812.3 12.047 11.908 11.812 12.020 11.926 11.879 11.862 11.859 11.963 11.912 — 12.69 12.46 12.626 J063140.00+050556.4 9.684 8.956 8.274 10.209 11.272 9.477 — — — — — — — —7 J063235.43+045158.6 12.227 11.902 11.829 12.244 11.928 11.864 11.837 12.015 11.794 11.698 — 13.20 12.80 12.948 J063230.89+044753.7 11.972 11.530 11.495 11.983 11.592 11.474 11.427 11.408 11.518 11.399 — 13.15 12.65 12.849 J063151.57+045417.5 11.981 11.314 10.613 12.057 11.611 10.828 9.974 9.560 8.479 6.669 2.591 13.38 12.98 12.9810 J063141.12+045607.6 11.634 11.096 10.966 11.608 11.349 10.981 10.870 10.885 10.796 10.836 — 13.42 12.71 13.0611 J063215.84+045430.0 11.583 10.947 10.769 11.652 11.148 10.825 10.705 10.681 10.622 10.458 — 13.68 12.87 13.2412 J063219.94+044819.1 11.842 11.320 11.122 11.816 11.371 11.133 11.051 10.988 10.933 10.849 — 13.75 12.99 13.4013 J063224.84+045746.2 12.613 12.175 12.075 12.597 12.189 12.079 12.023 12.132 11.956 11.985 — 13.78 13.26 13.4614 J063207.08+045629.8 11.783 11.162 11.022 11.778 11.290 10.992 10.869 10.801 11.082 10.455 9.152 13.85 13.07 13.4415 J063231.01+045005.9 12.070 11.571 11.092 12.120 11.572 11.041 10.345 10.056 9.674 8.544 5.986 13.90 13.22 13.5216 J063228.07+045403.7 12.327 11.794 11.661 12.254 11.808 11.618 11.541 11.647 11.499 11.524 — 13.98 13.28 13.6317 J063206.51+044755.3 11.970 11.224 10.344 12.593 11.567 10.329 8.949 8.454 7.971 7.449 5.548 13.48 12.98 13.1618 J063206.36+050236.8 13.118 12.808 12.644 13.123 12.814 12.659 12.552 12.563 12.529 12.561 — 14.64 14.03 14.3819 J063224.41+045222.6 12.872 12.225 12.074 12.771 12.219 12.014 11.895 11.899 11.838 11.791 — 14.80 14.02 14.4020 J063209.97+045423.1 12.893 12.305 12.095 12.847 12.307 12.100 12.049 12.053 11.991 11.962 — 14.88 14.12 14.4621 J063204.35+045758.1 12.954 12.477 12.369 13.026 12.577 12.391 12.252 12.275 12.213 12.296 — 14.76 14.07 14.4022 J063205.41+045659.2 12.608 11.940 11.764 12.675 12.039 11.792 11.684 11.700 11.569 11.586 — 14.98 14.09 14.5223 J063211.61+045357.0 12.967 12.270 12.107 12.914 12.288 12.056 12.072 11.983 12.044 11.942 — 15.23 14.35 14.8224 J063147.38+045320.3 13.064 12.414 12.106 13.037 12.468 12.240 12.054 12.085 12.064 12.178 — 15.09 14.28 14.7125 J063202.09+044855.4 13.116 12.488 12.210 13.087 12.482 12.258 12.142 12.180 12.136 12.108 — 15.27 14.42 14.9026 J063221.47+045027.4 13.134 12.409 12.181 13.055 12.406 12.168 12.061 12.072 12.073 12.004 — 15.39 14.49 15.0027 J063157.47+045504.4 13.438 12.789 12.590 13.397 12.780 12.564 12.535 12.598 12.427 12.308 — 15.52 14.70 15.0928 J063159.93+045109.9 13.266 12.580 12.348 13.290 12.654 12.412 12.312 12.196 12.071 12.092 — 15.52 14.64 15.0929 J063130.58+045835.7 14.405 13.965 13.841 14.361 13.953 13.858 — — — — — 15.81 15.23 15.4930 J063151.41+045728.4 13.097 12.306 12.088 12.948 12.301 12.054 11.957 11.923 11.880 11.755 — 15.47 14.54 14.9931 J063148.13+045337.9 13.124 12.418 12.218 13.101 12.476 12.236 12.220 12.163 12.089 12.050 — 15.45 14.57 15.0332 J063200.30+050041.9 13.178 12.421 12.203 13.158 12.480 12.235 12.015 12.114 12.029 11.976 — 15.56 14.62 15.1133 J063211.64+045027.0 13.646 12.988 12.821 13.646 13.034 12.810 12.736 12.657 12.668 12.528 — 15.82 14.98 15.4134 J063203.37+045235.9 13.132 12.345 11.971 13.725 12.963 12.447 11.478 11.313 10.911 10.193 7.806 15.30 14.40 14.8735 J063204.72+044914.8 13.524 12.848 12.622 13.480 12.852 12.635 12.669 12.617 12.598 12.412 — 15.78 14.91 15.3736 J063133.43+045825.9 14.638 14.283 14.008 14.615 14.238 14.146 — — — — — 16.05 15.47 15.7437 J063128.44+045450.3 13.753 13.089 12.884 13.736 13.129 12.941 — — — — — 15.96 15.13 15.5738 J063206.02+045031.2 13.298 12.570 12.374 13.319 12.610 12.357 12.260 12.371 12.235 12.182 — 15.81 14.84 15.3639 J063156.29+045416.1 13.261 12.473 12.252 13.214 12.523 12.258 12.160 12.277 12.125 12.113 — 15.88 14.89 15.3640 J063205.89+045705.3 13.177 12.399 12.192 13.174 12.469 12.199 11.993 12.003 11.930 11.878 — 15.86 14.83 15.3341 J063150.55+045553.0 13.199 12.365 12.136 13.139 12.413 12.131 11.996 11.996 11.841 11.924 — 15.90 14.82 15.3542 J063200.93+045155.9 13.413 12.632 12.340 13.314 12.599 12.275 11.927 11.413 10.494 9.146 6.151 15.85 14.86 15.3843 J063202.10+045647.1 13.327 12.597 12.334 13.295 12.611 12.350 12.169 12.145 12.097 11.997 — 15.87 14.89 15.3744 J063157.30+045451.4 13.117 12.299 12.008 13.123 12.412 12.093 11.726 11.539 11.528 11.162 7.731 16.04 15.00 15.4445 J063143.85+050257.4 13.273 12.379 11.973 13.154 12.365 11.990 11.146 10.703 10.117 9.063 4.920 16.62 15.42 15.8946 J063230.92+045007.2 — — — — 13.064 12.841 — — — — — 16.29 15.45 15.8547 J063215.02+045235.4 13.345 12.503 11.985 13.738 12.808 12.137 11.508 11.214 11.164 10.827 6.375 16.22 15.25 15.6048 J063151.63+045124.0 13.155 12.365 12.125 13.166 12.425 12.147 11.978 11.941 11.851 11.752 — 16.03 14.92 15.4949 J063148.30+045820.2 12.428 11.573 11.084 12.538 11.724 11.429 10.457 10.119 9.908 9.456 6.390 — — —50 J063204.53+045325.0 13.589 12.705 12.226 13.541 12.770 12.324 11.513 11.241 10.996 10.362 7.069 16.16 15.22 15.5951 J063213.83+044936.5 13.851 13.074 12.811 13.753 13.041 12.806 12.712 12.816 12.624 12.745 — 16.29 15.33 15.8352 J063205.21+044827.8 14.779 14.314 14.073 14.752 14.304 14.138 — — — — — 16.45 15.76 16.1453 J063221.40+045403.9 14.130 13.450 13.291 14.134 13.516 13.319 — — — — — 16.20 15.39 15.8054 J063207.71+050524.3 14.474 14.017 13.756 14.942 14.572 14.431 — — — — — 16.38 15.65 16.0355 J063125.81+045814.0 13.637 12.941 12.612 13.702 13.043 12.785 12.516 12.510 12.435 12.545 — 16.25 15.26 15.7056 J063231.59+045525.0 13.434 12.688 12.399 13.401 12.662 12.405 12.299 12.265 12.184 11.940 — 16.23 15.14 15.7057 J063223.18+050057.1 13.670 12.902 12.703 13.777 13.081 12.804 12.593 12.539 12.596 12.405 — 16.25 15.32 15.8358 J063206.69+045530.5 13.570 12.725 12.449 13.433 12.689 12.331 11.902 11.547 11.077 10.050 7.040 16.32 15.25 15.7959 J063132.01+050516.1 14.289 13.607 13.418 14.280 13.676 13.437 — — — — — 16.42 15.61 16.0560 J063149.25+045700.8 13.700 12.847 12.269 13.788 12.966 12.354 11.572 11.177 10.791 10.137 — 16.29 15.30 15.6161 J063141.98+045418.2 13.887 13.175 12.896 13.937 13.237 12.863 12.465 12.189 12.003 11.171 6.183 16.48 15.59 15.5262 J063150.78+045434.7 13.825 13.006 12.787 13.660 12.970 12.684 12.561 12.537 12.495 12.604 — 16.32 15.33 15.8163 J063140.86+045901.0 15.052 14.592 14.322 15.081 14.617 14.472 — — — — — 16.68 16.06 16.3764 J063218.03+044902.0 13.914 13.103 12.828 13.833 13.101 12.849 12.927 12.748 12.770 12.681 — 16.59 15.56 16.1065 J063216.13+045529.9 13.075 12.171 11.487 13.421 12.370 11.475 10.461 9.983 9.513 8.369 5.002 17.58 16.39 16.7566 J063159.25+050117.1 13.488 12.645 12.233 13.402 12.584 12.107 11.485 11.230 10.922 10.395 7.157 16.33 15.18 15.7667 J063128.83+045213.1 13.621 12.770 12.400 13.573 12.844 12.388 11.341 10.933 10.522 9.971 7.706 16.46 15.42 15.5268 J063159.33+050559.9 14.796 14.189 14.015 14.744 14.232 14.029 — — — — — 16.59 15.82 16.1769 J063217.57+045308.2 14.002 13.123 12.689 13.935 13.064 12.457 11.635 11.347 10.947 10.466 7.487 16.69 15.69 16.2770 J063220.82+050416.4 13.901 13.037 12.778 14.037 13.233 12.796 12.442 12.075 11.875 10.904 7.144 16.30 15.36 15.83 c (cid:13) , 1–, 1–
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag1 J063200.60+045240.9 8.152 8.125 8.120 10.825 11.668 9.523 8.376 8.311 8.197 8.184 — — — —2 J063133.11+045035.4 10.770 9.942 9.115 10.715 10.823 9.641 7.713 7.136 6.435 5.484 2.707 — — —3 J063129.76+045449.1 11.449 10.887 9.690 11.371 11.148 9.843 7.422 6.753 6.061 4.740 1.783 12.22 11.89 11.574 J063125.42+050209.3 10.977 10.711 10.544 10.913 11.005 10.560 — — — — — — — —5 J063130.87+045812.3 12.047 11.908 11.812 12.020 11.926 11.879 11.862 11.859 11.963 11.912 — 12.69 12.46 12.626 J063140.00+050556.4 9.684 8.956 8.274 10.209 11.272 9.477 — — — — — — — —7 J063235.43+045158.6 12.227 11.902 11.829 12.244 11.928 11.864 11.837 12.015 11.794 11.698 — 13.20 12.80 12.948 J063230.89+044753.7 11.972 11.530 11.495 11.983 11.592 11.474 11.427 11.408 11.518 11.399 — 13.15 12.65 12.849 J063151.57+045417.5 11.981 11.314 10.613 12.057 11.611 10.828 9.974 9.560 8.479 6.669 2.591 13.38 12.98 12.9810 J063141.12+045607.6 11.634 11.096 10.966 11.608 11.349 10.981 10.870 10.885 10.796 10.836 — 13.42 12.71 13.0611 J063215.84+045430.0 11.583 10.947 10.769 11.652 11.148 10.825 10.705 10.681 10.622 10.458 — 13.68 12.87 13.2412 J063219.94+044819.1 11.842 11.320 11.122 11.816 11.371 11.133 11.051 10.988 10.933 10.849 — 13.75 12.99 13.4013 J063224.84+045746.2 12.613 12.175 12.075 12.597 12.189 12.079 12.023 12.132 11.956 11.985 — 13.78 13.26 13.4614 J063207.08+045629.8 11.783 11.162 11.022 11.778 11.290 10.992 10.869 10.801 11.082 10.455 9.152 13.85 13.07 13.4415 J063231.01+045005.9 12.070 11.571 11.092 12.120 11.572 11.041 10.345 10.056 9.674 8.544 5.986 13.90 13.22 13.5216 J063228.07+045403.7 12.327 11.794 11.661 12.254 11.808 11.618 11.541 11.647 11.499 11.524 — 13.98 13.28 13.6317 J063206.51+044755.3 11.970 11.224 10.344 12.593 11.567 10.329 8.949 8.454 7.971 7.449 5.548 13.48 12.98 13.1618 J063206.36+050236.8 13.118 12.808 12.644 13.123 12.814 12.659 12.552 12.563 12.529 12.561 — 14.64 14.03 14.3819 J063224.41+045222.6 12.872 12.225 12.074 12.771 12.219 12.014 11.895 11.899 11.838 11.791 — 14.80 14.02 14.4020 J063209.97+045423.1 12.893 12.305 12.095 12.847 12.307 12.100 12.049 12.053 11.991 11.962 — 14.88 14.12 14.4621 J063204.35+045758.1 12.954 12.477 12.369 13.026 12.577 12.391 12.252 12.275 12.213 12.296 — 14.76 14.07 14.4022 J063205.41+045659.2 12.608 11.940 11.764 12.675 12.039 11.792 11.684 11.700 11.569 11.586 — 14.98 14.09 14.5223 J063211.61+045357.0 12.967 12.270 12.107 12.914 12.288 12.056 12.072 11.983 12.044 11.942 — 15.23 14.35 14.8224 J063147.38+045320.3 13.064 12.414 12.106 13.037 12.468 12.240 12.054 12.085 12.064 12.178 — 15.09 14.28 14.7125 J063202.09+044855.4 13.116 12.488 12.210 13.087 12.482 12.258 12.142 12.180 12.136 12.108 — 15.27 14.42 14.9026 J063221.47+045027.4 13.134 12.409 12.181 13.055 12.406 12.168 12.061 12.072 12.073 12.004 — 15.39 14.49 15.0027 J063157.47+045504.4 13.438 12.789 12.590 13.397 12.780 12.564 12.535 12.598 12.427 12.308 — 15.52 14.70 15.0928 J063159.93+045109.9 13.266 12.580 12.348 13.290 12.654 12.412 12.312 12.196 12.071 12.092 — 15.52 14.64 15.0929 J063130.58+045835.7 14.405 13.965 13.841 14.361 13.953 13.858 — — — — — 15.81 15.23 15.4930 J063151.41+045728.4 13.097 12.306 12.088 12.948 12.301 12.054 11.957 11.923 11.880 11.755 — 15.47 14.54 14.9931 J063148.13+045337.9 13.124 12.418 12.218 13.101 12.476 12.236 12.220 12.163 12.089 12.050 — 15.45 14.57 15.0332 J063200.30+050041.9 13.178 12.421 12.203 13.158 12.480 12.235 12.015 12.114 12.029 11.976 — 15.56 14.62 15.1133 J063211.64+045027.0 13.646 12.988 12.821 13.646 13.034 12.810 12.736 12.657 12.668 12.528 — 15.82 14.98 15.4134 J063203.37+045235.9 13.132 12.345 11.971 13.725 12.963 12.447 11.478 11.313 10.911 10.193 7.806 15.30 14.40 14.8735 J063204.72+044914.8 13.524 12.848 12.622 13.480 12.852 12.635 12.669 12.617 12.598 12.412 — 15.78 14.91 15.3736 J063133.43+045825.9 14.638 14.283 14.008 14.615 14.238 14.146 — — — — — 16.05 15.47 15.7437 J063128.44+045450.3 13.753 13.089 12.884 13.736 13.129 12.941 — — — — — 15.96 15.13 15.5738 J063206.02+045031.2 13.298 12.570 12.374 13.319 12.610 12.357 12.260 12.371 12.235 12.182 — 15.81 14.84 15.3639 J063156.29+045416.1 13.261 12.473 12.252 13.214 12.523 12.258 12.160 12.277 12.125 12.113 — 15.88 14.89 15.3640 J063205.89+045705.3 13.177 12.399 12.192 13.174 12.469 12.199 11.993 12.003 11.930 11.878 — 15.86 14.83 15.3341 J063150.55+045553.0 13.199 12.365 12.136 13.139 12.413 12.131 11.996 11.996 11.841 11.924 — 15.90 14.82 15.3542 J063200.93+045155.9 13.413 12.632 12.340 13.314 12.599 12.275 11.927 11.413 10.494 9.146 6.151 15.85 14.86 15.3843 J063202.10+045647.1 13.327 12.597 12.334 13.295 12.611 12.350 12.169 12.145 12.097 11.997 — 15.87 14.89 15.3744 J063157.30+045451.4 13.117 12.299 12.008 13.123 12.412 12.093 11.726 11.539 11.528 11.162 7.731 16.04 15.00 15.4445 J063143.85+050257.4 13.273 12.379 11.973 13.154 12.365 11.990 11.146 10.703 10.117 9.063 4.920 16.62 15.42 15.8946 J063230.92+045007.2 — — — — 13.064 12.841 — — — — — 16.29 15.45 15.8547 J063215.02+045235.4 13.345 12.503 11.985 13.738 12.808 12.137 11.508 11.214 11.164 10.827 6.375 16.22 15.25 15.6048 J063151.63+045124.0 13.155 12.365 12.125 13.166 12.425 12.147 11.978 11.941 11.851 11.752 — 16.03 14.92 15.4949 J063148.30+045820.2 12.428 11.573 11.084 12.538 11.724 11.429 10.457 10.119 9.908 9.456 6.390 — — —50 J063204.53+045325.0 13.589 12.705 12.226 13.541 12.770 12.324 11.513 11.241 10.996 10.362 7.069 16.16 15.22 15.5951 J063213.83+044936.5 13.851 13.074 12.811 13.753 13.041 12.806 12.712 12.816 12.624 12.745 — 16.29 15.33 15.8352 J063205.21+044827.8 14.779 14.314 14.073 14.752 14.304 14.138 — — — — — 16.45 15.76 16.1453 J063221.40+045403.9 14.130 13.450 13.291 14.134 13.516 13.319 — — — — — 16.20 15.39 15.8054 J063207.71+050524.3 14.474 14.017 13.756 14.942 14.572 14.431 — — — — — 16.38 15.65 16.0355 J063125.81+045814.0 13.637 12.941 12.612 13.702 13.043 12.785 12.516 12.510 12.435 12.545 — 16.25 15.26 15.7056 J063231.59+045525.0 13.434 12.688 12.399 13.401 12.662 12.405 12.299 12.265 12.184 11.940 — 16.23 15.14 15.7057 J063223.18+050057.1 13.670 12.902 12.703 13.777 13.081 12.804 12.593 12.539 12.596 12.405 — 16.25 15.32 15.8358 J063206.69+045530.5 13.570 12.725 12.449 13.433 12.689 12.331 11.902 11.547 11.077 10.050 7.040 16.32 15.25 15.7959 J063132.01+050516.1 14.289 13.607 13.418 14.280 13.676 13.437 — — — — — 16.42 15.61 16.0560 J063149.25+045700.8 13.700 12.847 12.269 13.788 12.966 12.354 11.572 11.177 10.791 10.137 — 16.29 15.30 15.6161 J063141.98+045418.2 13.887 13.175 12.896 13.937 13.237 12.863 12.465 12.189 12.003 11.171 6.183 16.48 15.59 15.5262 J063150.78+045434.7 13.825 13.006 12.787 13.660 12.970 12.684 12.561 12.537 12.495 12.604 — 16.32 15.33 15.8163 J063140.86+045901.0 15.052 14.592 14.322 15.081 14.617 14.472 — — — — — 16.68 16.06 16.3764 J063218.03+044902.0 13.914 13.103 12.828 13.833 13.101 12.849 12.927 12.748 12.770 12.681 — 16.59 15.56 16.1065 J063216.13+045529.9 13.075 12.171 11.487 13.421 12.370 11.475 10.461 9.983 9.513 8.369 5.002 17.58 16.39 16.7566 J063159.25+050117.1 13.488 12.645 12.233 13.402 12.584 12.107 11.485 11.230 10.922 10.395 7.157 16.33 15.18 15.7667 J063128.83+045213.1 13.621 12.770 12.400 13.573 12.844 12.388 11.341 10.933 10.522 9.971 7.706 16.46 15.42 15.5268 J063159.33+050559.9 14.796 14.189 14.015 14.744 14.232 14.029 — — — — — 16.59 15.82 16.1769 J063217.57+045308.2 14.002 13.123 12.689 13.935 13.064 12.457 11.635 11.347 10.947 10.466 7.487 16.69 15.69 16.2770 J063220.82+050416.4 13.901 13.037 12.778 14.037 13.233 12.796 12.442 12.075 11.875 10.904 7.144 16.30 15.36 15.83 c (cid:13) , 1–, 1– ?? G. Michalska
Star Name
J H K S J H K [3 .
6] [4 .
5] [5 .
8] [8 .
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag71 J063214.74+045023.6 13.794 12.906 12.676 13.780 12.999 12.723 12.728 12.581 12.604 12.609 — 16.55 15.44 16.0172 J063134.30+050416.0 — — — 15.138 14.812 14.535 — — — — — 16.89 16.25 16.6373 J063205.92+045727.6 13.449 12.502 12.068 13.622 12.735 12.176 11.887 11.212 10.869 9.991 6.671 16.70 15.50 15.9074 J063157.34+045342.3 13.958 13.091 12.824 13.934 13.208 12.910 12.233 12.060 11.874 11.360 — 16.40 15.45 15.9675 J063143.91+050238.9 14.923 14.384 14.376 14.858 14.449 14.256 — — — — — 16.87 16.08 16.6076 J063207.82+045228.4 14.030 13.208 12.764 14.067 13.225 12.683 11.990 11.504 11.249 10.485 8.159 16.74 15.73 15.9577 J063151.48+045132.0 13.398 12.573 12.195 13.665 12.805 12.334 11.663 11.418 11.142 10.747 8.500 16.82 15.58 16.1678 J063220.34+045841.7 13.860 13.065 12.780 13.810 13.053 12.775 12.719 12.652 12.639 12.668 — 16.85 15.69 16.2579 J063208.01+045033.5 13.933 13.088 12.806 13.856 13.116 12.802 12.583 12.514 12.496 12.426 — 16.53 15.46 16.1080 J063204.68+044745.5 13.726 12.849 12.282 13.873 13.039 12.506 11.861 11.608 11.086 10.519 8.347 16.70 15.67 16.1281 J063157.18+045011.9 13.749 12.854 12.625 13.700 12.957 12.644 12.560 12.467 12.571 12.460 — 16.66 15.48 16.0882 J063151.64+045505.2 13.908 13.013 12.452 13.915 13.127 12.637 11.932 11.593 11.422 10.831 6.583 16.85 15.80 16.2483 J063127.84+045002.9 13.792 12.802 12.006 13.491 12.531 11.613 10.551 10.096 9.658 8.979 6.007 16.42 15.60 15.2684 J063216.67+044938.2 14.231 13.414 13.063 14.118 13.395 13.137 12.369 11.963 11.565 10.409 5.509 16.80 15.78 16.3085 J063220.25+045755.6 14.063 13.193 12.940 14.033 13.295 13.031 12.658 12.557 12.358 12.211 — 16.75 15.69 16.2686 J063205.44+045729.9 13.888 13.066 12.788 13.902 13.142 12.878 12.693 12.706 12.651 12.766 — 16.72 15.58 16.1687 J063159.12+045525.9 13.733 12.866 12.561 13.702 12.942 12.596 12.096 11.901 11.674 11.188 — 16.82 15.64 16.2188 J063141.02+045447.8 14.178 13.363 12.954 14.118 13.345 12.890 12.273 11.967 11.601 10.800 8.314 16.68 15.72 15.9489 J063223.11+044943.2 13.649 12.700 12.286 13.643 12.768 12.279 11.715 11.450 11.120 10.478 7.296 16.80 15.55 16.2790 J063150.44+045638.2 13.111 13.038 12.783 13.802 13.116 12.801 12.308 12.157 11.927 11.696 — 16.68 15.58 16.1291 J063222.77+050031.8 14.259 13.513 13.303 14.215 13.471 13.240 13.130 13.119 12.943 13.065 — 16.96 15.94 16.5392 J063130.02+050045.6 14.824 14.327 14.028 14.815 14.387 14.087 — — — — — 17.07 16.21 16.8193 J063210.65+045132.7 14.200 13.407 13.137 14.138 13.409 13.131 13.120 12.948 12.942 13.047 — 16.97 15.89 16.5494 J063121.42+045405.7 14.060 13.249 12.998 13.982 13.278 13.007 — — — — — 16.78 15.71 16.2995 J063143.88+050356.5 14.366 13.620 13.379 14.450 13.767 13.491 — — — — — 16.88 15.93 16.4296 J063223.41+045239.1 13.879 13.012 12.692 13.872 13.089 12.740 12.360 12.167 11.917 11.335 7.676 16.85 15.65 16.2297 J063144.47+050342.2 14.179 13.379 13.138 14.140 13.436 13.152 13.037 13.011 13.028 12.838 — 16.84 15.77 16.2898 J063136.42+045313.8 13.843 12.930 12.511 13.832 13.021 12.501 12.062 11.507 11.130 10.316 7.467 17.15 15.98 16.4499 J063204.66+045451.5 13.801 12.920 12.538 13.732 12.959 12.568 12.040 11.813 11.624 11.042 8.214 16.70 15.57 16.00100 J063146.07+045430.7 14.001 13.176 12.874 13.982 13.269 12.965 12.917 12.783 12.817 12.749 — 16.98 15.83 16.45101 J063150.25+050007.6 14.214 13.473 13.107 14.211 13.451 13.162 12.942 12.793 12.539 12.171 9.160 16.92 15.83 16.38102 J063120.86+050408.5 14.068 13.227 12.711 14.357 13.464 12.947 12.188 11.974 11.745 11.030 7.401 16.91 15.85 16.35103 J063138.78+045524.8 14.035 13.258 12.975 14.058 13.319 13.055 12.816 12.800 12.758 12.605 — 16.99 15.83 16.40104 J063150.43+045150.1 14.224 13.339 12.796 14.298 13.412 12.836 12.244 11.963 11.805 11.460 7.143 17.20 16.14 16.35105 J063220.79+045258.2 14.216 13.411 13.274 14.225 13.475 13.206 13.040 12.894 12.953 12.898 — 16.98 15.89 16.40106 J063201.15+045527.3 14.148 13.344 13.143 14.205 13.467 13.206 12.904 12.744 12.644 12.230 — 16.82 15.75 16.28107 J063214.81+044855.3 14.372 13.577 13.343 14.414 13.661 13.386 13.223 13.207 13.190 13.118 — 17.06 16.00 16.57108 J063147.56+044907.7 14.301 13.588 13.256 14.266 13.545 13.266 13.054 13.053 12.933 13.158 — 17.13 16.02 16.62109 J063155.25+045329.9 14.096 13.316 13.111 14.165 13.483 13.192 13.007 13.008 12.832 13.181 — 17.04 15.93 16.53110 J063210.88+045706.1 14.403 13.620 13.388 14.370 13.632 13.381 13.272 13.228 13.069 13.100 — 17.01 16.00 16.48111 J063155.81+045127.3 14.243 13.424 13.170 14.190 13.453 13.153 — — — — — 17.21 16.05 16.67112 J063155.60+045517.2 — — — 14.432 13.608 13.198 12.722 12.632 12.374 11.877 7.660 17.02 15.98 16.42113 J063145.37+045902.3 14.241 13.401 13.149 14.128 13.376 13.095 12.914 12.897 12.850 12.654 — 16.87 15.85 16.40114 J063223.83+050613.6 — — — 15.675 15.018 15.046 — — — — — — — —115 J063157.60+050229.1 14.410 13.496 13.204 14.215 13.463 13.101 12.672 12.407 12.087 11.425 — 17.18 16.01 16.52116 J063136.86+045104.3 13.634 12.650 12.059 13.423 12.552 11.873 11.592 11.124 10.527 9.288 5.913 16.11 15.08 15.63117 J063229.24+050515.8 14.617 13.824 13.611 14.612 13.860 13.623 — — — — — 17.20 16.18 16.57118 J063127.65+045402.7 13.936 13.154 12.815 13.941 13.204 12.901 12.751 12.682 12.573 12.435 — 17.07 15.78 16.45119 J063200.57+050533.4 14.095 13.397 13.318 14.317 13.882 13.593 — — — — — — — —120 J063225.12+045514.3 14.380 13.563 13.084 14.572 13.780 13.338 12.442 12.229 11.896 11.361 9.181 17.37 16.31 16.91121 J063155.51+045346.8 — — — 14.179 13.432 13.086 12.464 12.118 11.761 10.899 8.346 17.29 16.11 16.69122 J063148.72+045520.9 14.588 13.742 13.412 14.496 13.758 13.472 — — — — — 17.18 16.11 16.65123 J063200.47+045946.8 14.520 13.680 13.470 14.402 13.684 13.391 13.241 13.240 13.104 12.966 — 17.39 16.27 16.84124 J063155.02+045320.8 14.212 13.328 13.102 14.208 13.457 13.121 12.971 12.931 12.809 12.797 — 17.17 15.98 16.59125 J063209.91+045015.0 14.583 13.701 13.460 14.577 13.806 13.532 — — — — — 17.27 16.21 16.80126 J063207.55+045615.2 14.122 13.328 13.088 14.132 13.388 13.076 12.919 13.091 12.725 12.872 — 17.31 16.06 16.70127 J063210.91+045502.4 14.637 13.789 13.420 14.617 13.828 13.408 12.922 12.628 12.225 11.577 — 17.38 16.39 16.75128 J063227.18+045241.8 14.786 14.079 13.887 14.876 14.131 13.884 — — — — — 17.31 16.32 16.87129 J063147.43+045331.5 14.264 13.465 13.188 14.320 13.546 13.243 — — — — — 17.28 16.08 16.72130 J063147.69+045649.7 14.228 13.387 13.127 14.235 13.486 13.183 12.958 12.886 12.768 12.915 — 17.36 16.10 16.74131 J063205.07+045546.8 14.684 13.457 12.551 14.164 13.141 12.289 11.386 10.950 10.583 9.712 6.496 16.96 16.05 16.43132 J063156.92+045302.0 14.515 13.563 13.179 14.369 13.481 12.957 12.400 12.098 11.742 11.229 — 17.26 16.16 16.73133 J063201.83+045338.6 14.262 13.320 12.906 14.212 13.425 12.950 12.264 12.155 11.689 10.916 7.338 17.16 16.10 16.28134 J063136.76+045309.9 14.746 13.675 13.160 14.802 13.929 13.490 12.853 12.515 12.105 11.087 7.671 17.70 16.49 17.14135 J063154.59+045941.5 14.816 14.003 13.698 14.788 14.082 13.793 — — — — — 17.46 16.41 16.97136 J063157.08+045436.4 14.388 13.529 13.363 14.381 13.618 13.323 13.186 13.140 13.159 13.063 — 17.36 16.18 16.78137 J063208.28+045056.4 14.461 13.603 13.344 14.299 13.550 13.270 — — — — — 17.31 16.12 16.81138 J063202.92+045853.9 14.372 13.588 13.341 14.457 13.694 13.417 13.148 13.165 12.972 13.113 — 17.45 16.19 16.82139 J063152.00+045408.3 14.633 13.834 13.410 14.611 13.875 13.560 — — — — — 17.59 16.48 16.99140 J063207.66+045433.6 14.604 13.794 13.493 14.537 13.763 13.447 13.223 13.070 12.870 11.748 7.621 17.52 16.38 17.05 c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Star Name
J H K S J H K [3 .
6] [4 .
5] [5 .
8] [8 .
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag141 J063159.62+045216.8 14.161 13.353 13.160 14.168 13.439 13.127 12.868 12.845 12.745 12.589 — 16.95 15.86 16.39142 J063139.61+045945.0 14.117 13.132 12.650 14.099 13.192 12.627 12.005 11.655 11.484 10.823 7.916 17.64 16.20 16.74143 J063149.80+044906.8 14.372 13.501 13.216 14.389 13.630 13.303 13.024 12.993 13.035 12.890 — 17.47 16.18 16.81144 J063159.69+045535.9 14.320 13.471 13.292 14.352 13.574 13.277 13.151 13.063 13.135 12.960 — 17.57 16.27 16.99145 J063148.05+045048.3 14.152 13.253 12.763 14.311 13.427 12.843 12.194 11.725 11.129 10.210 7.033 17.53 16.20 16.48146 J063143.56+045949.0 14.450 13.652 13.360 14.478 13.720 13.427 — — — — — 17.58 16.38 16.99147 J063130.24+045148.3 14.612 13.623 13.190 14.649 13.799 13.227 12.300 11.916 11.651 11.116 7.916 17.94 16.73 17.15148 J063137.21+045657.2 14.715 13.917 13.716 14.753 13.997 13.759 — — — — — 17.45 16.36 16.95149 J063201.02+045731.7 14.608 13.633 13.142 14.863 13.929 13.374 12.493 12.220 11.762 11.106 — 17.57 16.42 16.86150 J063147.45+045832.7 14.658 13.874 13.566 14.547 13.767 13.474 13.286 13.278 13.205 13.063 — 17.66 16.52 17.17151 J063215.12+045957.4 14.490 13.672 13.364 14.397 13.616 13.336 13.158 13.142 13.115 12.801 — — — —152 J063147.58+045052.9 14.205 13.137 12.630 14.195 13.309 12.741 11.702 11.386 11.057 10.259 6.765 17.47 16.16 16.74153 J063225.76+045823.1 14.358 13.491 13.229 14.260 13.493 13.209 — — — — — 17.64 16.24 16.99154 J063222.26+044714.0 14.430 13.504 13.310 14.727 13.871 13.543 13.058 13.029 12.918 13.018 — 17.66 16.28 16.81155 J063139.55+045338.5 14.619 13.622 13.050 14.648 13.782 13.142 12.363 12.351 11.923 10.994 — 17.81 16.72 16.65156 J063209.32+045241.4 14.295 13.455 13.221 14.332 13.568 13.271 13.098 13.022 13.019 13.098 — 17.49 16.12 16.64157 J063152.55+045817.2 14.522 13.732 13.447 14.563 13.818 13.511 13.249 13.224 13.000 13.174 — 17.61 16.41 17.01158 J063156.78+045351.0 14.699 13.873 13.352 14.737 13.974 13.622 13.182 13.020 12.843 11.845 7.222 17.66 16.50 17.09159 J063146.10+045750.7 14.687 13.913 13.679 14.697 13.968 13.676 — — — — — 17.67 16.53 17.13160 J063132.09+045738.7 14.852 13.978 13.704 14.776 14.016 13.732 13.345 13.136 13.043 12.194 8.156 17.76 16.61 17.17161 J063145.11+045126.2 14.905 14.127 13.837 14.823 14.070 13.788 — — — — — 17.93 16.68 17.38162 J063158.14+044829.8 14.723 13.890 13.651 14.754 13.968 13.660 — — — — — 17.98 16.75 17.40163 J063130.95+044848.3 14.606 13.687 13.194 14.638 13.811 13.364 12.800 12.529 12.239 11.073 8.170 17.95 16.60 17.24164 J063212.21+045632.7 14.833 14.054 13.721 14.855 14.058 13.793 — — — — — 17.84 16.67 17.49165 J063139.17+044959.4 14.824 13.662 12.933 14.950 13.964 13.211 12.508 12.107 11.811 10.929 7.308 18.06 16.86 16.92166 J063148.89+045609.2 14.807 14.002 13.566 14.837 14.090 13.710 13.186 12.924 12.451 11.715 — 17.54 16.47 16.96167 J063139.30+045400.9 14.418 13.613 13.346 14.512 13.755 13.446 — — — — — 17.74 16.42 17.09168 J063230.05+045726.2 14.989 14.153 14.014 15.004 14.227 13.964 — — — — — 17.95 16.79 17.23169 J063141.97+045416.2 — — — 14.713 13.988 13.676 — — — — — 18.06 16.79 17.11170 J063124.42+045305.4 — — — 15.758 15.168 14.932 — — — — — 18.36 17.43 17.79171 J063149.52+045200.0 15.281 14.458 14.273 15.150 14.414 14.144 — — — — — 17.86 16.78 17.47172 J063148.31+045238.8 14.179 13.935 13.364 14.730 13.840 13.314 12.764 12.537 12.163 11.601 8.017 17.87 16.58 17.18173 J063156.53+045428.3 14.811 13.949 13.687 14.755 13.979 13.680 13.509 13.518 13.381 13.221 — 17.97 16.67 17.37174 J063141.13+045551.4 14.880 14.021 13.727 14.841 14.053 13.775 — — — — — 17.88 16.68 17.38175 J063201.49+045445.0 14.569 13.656 13.124 14.485 13.643 13.118 12.249 11.855 11.504 10.507 7.474 17.62 16.40 16.98176 J063201.10+045449.7 14.400 13.692 13.388 14.380 13.669 13.337 — — — — — 17.96 16.49 17.35177 J063206.48+044846.5 14.792 13.873 13.565 14.652 13.842 13.547 13.494 13.403 13.308 13.082 — 17.84 16.58 17.33178 J063141.57+045940.4 15.094 14.276 14.069 15.033 14.269 13.999 — — — — — 18.10 16.91 17.52179 J063212.33+045721.7 15.176 14.072 13.443 14.837 13.953 13.527 12.504 12.107 11.746 11.155 8.541 18.08 16.79 17.37180 J063226.57+045238.3 14.901 13.914 13.589 14.965 14.157 13.714 12.848 12.447 12.067 11.162 8.126 18.02 16.86 16.76181 J063141.90+045046.1 15.021 14.184 13.789 14.874 14.093 13.646 13.350 13.116 12.986 12.530 8.148 18.26 17.01 17.44182 J063212.85+045837.9 14.546 13.777 13.575 14.662 13.902 13.573 13.274 13.226 13.262 13.041 — 17.97 16.65 17.38183 J063143.35+045724.8 15.181 14.273 13.911 15.249 14.376 13.979 13.313 13.063 12.816 12.298 — 18.06 16.81 17.35184 J063153.77+044847.0 14.535 13.608 13.298 14.550 13.741 13.441 13.160 13.133 13.088 13.110 — 18.13 16.53 17.33185 J063212.18+050139.8 15.252 14.317 13.934 15.196 14.436 14.036 13.635 13.188 12.821 12.319 — 18.22 17.04 17.68186 J063144.91+045600.1 14.117 13.192 12.625 14.281 13.354 12.658 12.047 11.609 11.289 10.720 — 18.68 17.03 17.71187 J063147.79+045223.9 15.149 14.101 13.367 14.877 13.949 13.325 12.580 12.027 11.495 10.633 7.767 18.41 17.10 17.66188 J063150.35+045738.9 14.754 13.925 13.633 14.779 14.011 13.690 — — — — — 18.15 16.72 17.43189 J063118.43+045440.1 14.932 14.086 13.652 14.942 14.113 13.704 — — — — — 18.48 17.27 17.66190 J063204.46+045826.1 14.885 13.959 13.706 14.894 14.126 13.790 13.337 13.190 13.087 12.550 — 18.12 16.85 17.37191 J063216.16+045920.0 14.761 13.856 13.535 14.685 13.862 13.446 13.077 12.803 12.436 11.524 7.253 17.87 16.62 17.37192 J063156.86+045514.7 14.639 13.802 13.509 14.645 13.873 13.541 — — — — — 18.22 16.75 17.49193 J063154.92+045136.1 15.152 14.241 14.037 15.166 14.324 13.967 — — — — — 18.26 17.00 17.18194 J063230.12+045522.1 15.221 14.120 13.594 15.342 14.297 13.563 12.666 12.473 12.129 11.649 9.101 18.61 17.24 17.48195 J063159.29+045137.5 15.057 14.254 14.002 15.104 14.344 14.016 — — — — — 17.97 16.75 17.50196 J063139.87+045639.1 15.053 14.099 13.615 15.086 14.182 13.693 12.894 12.675 12.557 12.431 — 18.12 16.97 17.00197 J063203.08+050134.8 — — — 15.115 14.204 13.626 13.038 12.731 12.296 11.431 7.793 18.42 17.15 17.30198 J063206.98+044803.7 15.148 14.327 14.068 15.198 14.386 14.094 — — — — — 18.35 17.05 17.66199 J063119.47+045309.6 14.828 13.963 13.574 14.851 14.011 13.699 — — — — — 18.29 16.86 17.55200 J063158.91+045743.0 15.307 14.407 13.995 15.176 14.380 13.983 13.565 13.369 12.975 12.229 — 18.31 17.03 17.65201 J063201.50+045502.2 15.170 14.232 13.953 15.187 14.417 14.109 — — — — — 18.13 16.88 17.46202 J063142.58+045256.1 14.717 13.801 13.523 14.684 13.915 13.482 12.477 12.029 11.510 10.717 8.332 18.24 16.69 17.31203 J063227.50+045251.3 14.791 13.810 13.291 14.810 13.927 13.361 12.506 12.305 11.828 11.318 8.036 17.95 16.72 16.88204 J063158.89+045811.0 15.092 14.188 13.741 15.016 14.181 13.673 12.995 12.618 12.015 11.079 — 18.22 17.07 16.92205 J063220.33+045320.7 — — — 16.371 15.790 15.621 — — — — — 18.57 17.65 17.78206 J063205.07+045226.7 14.898 14.070 13.917 14.880 14.110 13.711 13.429 13.320 13.209 12.671 9.495 18.31 16.85 17.36207 J063235.67+044745.8 16.015 14.689 13.978 15.453 14.280 13.573 12.815 12.250 11.677 10.606 7.075 — — —208 J063130.72+045214.9 15.295 14.317 13.909 15.249 14.484 14.120 13.476 13.182 13.092 12.017 8.947 18.53 17.18 17.93209 J063151.55+044727.9 15.185 14.235 13.511 15.253 14.222 13.510 12.406 11.785 11.306 10.358 7.449 18.71 17.28 17.45210 J063152.20+045240.0 15.234 14.430 13.965 15.269 14.482 14.094 13.530 13.158 12.833 11.995 — 18.83 17.34 17.94 c (cid:13) , 1–, 1–
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag141 J063159.62+045216.8 14.161 13.353 13.160 14.168 13.439 13.127 12.868 12.845 12.745 12.589 — 16.95 15.86 16.39142 J063139.61+045945.0 14.117 13.132 12.650 14.099 13.192 12.627 12.005 11.655 11.484 10.823 7.916 17.64 16.20 16.74143 J063149.80+044906.8 14.372 13.501 13.216 14.389 13.630 13.303 13.024 12.993 13.035 12.890 — 17.47 16.18 16.81144 J063159.69+045535.9 14.320 13.471 13.292 14.352 13.574 13.277 13.151 13.063 13.135 12.960 — 17.57 16.27 16.99145 J063148.05+045048.3 14.152 13.253 12.763 14.311 13.427 12.843 12.194 11.725 11.129 10.210 7.033 17.53 16.20 16.48146 J063143.56+045949.0 14.450 13.652 13.360 14.478 13.720 13.427 — — — — — 17.58 16.38 16.99147 J063130.24+045148.3 14.612 13.623 13.190 14.649 13.799 13.227 12.300 11.916 11.651 11.116 7.916 17.94 16.73 17.15148 J063137.21+045657.2 14.715 13.917 13.716 14.753 13.997 13.759 — — — — — 17.45 16.36 16.95149 J063201.02+045731.7 14.608 13.633 13.142 14.863 13.929 13.374 12.493 12.220 11.762 11.106 — 17.57 16.42 16.86150 J063147.45+045832.7 14.658 13.874 13.566 14.547 13.767 13.474 13.286 13.278 13.205 13.063 — 17.66 16.52 17.17151 J063215.12+045957.4 14.490 13.672 13.364 14.397 13.616 13.336 13.158 13.142 13.115 12.801 — — — —152 J063147.58+045052.9 14.205 13.137 12.630 14.195 13.309 12.741 11.702 11.386 11.057 10.259 6.765 17.47 16.16 16.74153 J063225.76+045823.1 14.358 13.491 13.229 14.260 13.493 13.209 — — — — — 17.64 16.24 16.99154 J063222.26+044714.0 14.430 13.504 13.310 14.727 13.871 13.543 13.058 13.029 12.918 13.018 — 17.66 16.28 16.81155 J063139.55+045338.5 14.619 13.622 13.050 14.648 13.782 13.142 12.363 12.351 11.923 10.994 — 17.81 16.72 16.65156 J063209.32+045241.4 14.295 13.455 13.221 14.332 13.568 13.271 13.098 13.022 13.019 13.098 — 17.49 16.12 16.64157 J063152.55+045817.2 14.522 13.732 13.447 14.563 13.818 13.511 13.249 13.224 13.000 13.174 — 17.61 16.41 17.01158 J063156.78+045351.0 14.699 13.873 13.352 14.737 13.974 13.622 13.182 13.020 12.843 11.845 7.222 17.66 16.50 17.09159 J063146.10+045750.7 14.687 13.913 13.679 14.697 13.968 13.676 — — — — — 17.67 16.53 17.13160 J063132.09+045738.7 14.852 13.978 13.704 14.776 14.016 13.732 13.345 13.136 13.043 12.194 8.156 17.76 16.61 17.17161 J063145.11+045126.2 14.905 14.127 13.837 14.823 14.070 13.788 — — — — — 17.93 16.68 17.38162 J063158.14+044829.8 14.723 13.890 13.651 14.754 13.968 13.660 — — — — — 17.98 16.75 17.40163 J063130.95+044848.3 14.606 13.687 13.194 14.638 13.811 13.364 12.800 12.529 12.239 11.073 8.170 17.95 16.60 17.24164 J063212.21+045632.7 14.833 14.054 13.721 14.855 14.058 13.793 — — — — — 17.84 16.67 17.49165 J063139.17+044959.4 14.824 13.662 12.933 14.950 13.964 13.211 12.508 12.107 11.811 10.929 7.308 18.06 16.86 16.92166 J063148.89+045609.2 14.807 14.002 13.566 14.837 14.090 13.710 13.186 12.924 12.451 11.715 — 17.54 16.47 16.96167 J063139.30+045400.9 14.418 13.613 13.346 14.512 13.755 13.446 — — — — — 17.74 16.42 17.09168 J063230.05+045726.2 14.989 14.153 14.014 15.004 14.227 13.964 — — — — — 17.95 16.79 17.23169 J063141.97+045416.2 — — — 14.713 13.988 13.676 — — — — — 18.06 16.79 17.11170 J063124.42+045305.4 — — — 15.758 15.168 14.932 — — — — — 18.36 17.43 17.79171 J063149.52+045200.0 15.281 14.458 14.273 15.150 14.414 14.144 — — — — — 17.86 16.78 17.47172 J063148.31+045238.8 14.179 13.935 13.364 14.730 13.840 13.314 12.764 12.537 12.163 11.601 8.017 17.87 16.58 17.18173 J063156.53+045428.3 14.811 13.949 13.687 14.755 13.979 13.680 13.509 13.518 13.381 13.221 — 17.97 16.67 17.37174 J063141.13+045551.4 14.880 14.021 13.727 14.841 14.053 13.775 — — — — — 17.88 16.68 17.38175 J063201.49+045445.0 14.569 13.656 13.124 14.485 13.643 13.118 12.249 11.855 11.504 10.507 7.474 17.62 16.40 16.98176 J063201.10+045449.7 14.400 13.692 13.388 14.380 13.669 13.337 — — — — — 17.96 16.49 17.35177 J063206.48+044846.5 14.792 13.873 13.565 14.652 13.842 13.547 13.494 13.403 13.308 13.082 — 17.84 16.58 17.33178 J063141.57+045940.4 15.094 14.276 14.069 15.033 14.269 13.999 — — — — — 18.10 16.91 17.52179 J063212.33+045721.7 15.176 14.072 13.443 14.837 13.953 13.527 12.504 12.107 11.746 11.155 8.541 18.08 16.79 17.37180 J063226.57+045238.3 14.901 13.914 13.589 14.965 14.157 13.714 12.848 12.447 12.067 11.162 8.126 18.02 16.86 16.76181 J063141.90+045046.1 15.021 14.184 13.789 14.874 14.093 13.646 13.350 13.116 12.986 12.530 8.148 18.26 17.01 17.44182 J063212.85+045837.9 14.546 13.777 13.575 14.662 13.902 13.573 13.274 13.226 13.262 13.041 — 17.97 16.65 17.38183 J063143.35+045724.8 15.181 14.273 13.911 15.249 14.376 13.979 13.313 13.063 12.816 12.298 — 18.06 16.81 17.35184 J063153.77+044847.0 14.535 13.608 13.298 14.550 13.741 13.441 13.160 13.133 13.088 13.110 — 18.13 16.53 17.33185 J063212.18+050139.8 15.252 14.317 13.934 15.196 14.436 14.036 13.635 13.188 12.821 12.319 — 18.22 17.04 17.68186 J063144.91+045600.1 14.117 13.192 12.625 14.281 13.354 12.658 12.047 11.609 11.289 10.720 — 18.68 17.03 17.71187 J063147.79+045223.9 15.149 14.101 13.367 14.877 13.949 13.325 12.580 12.027 11.495 10.633 7.767 18.41 17.10 17.66188 J063150.35+045738.9 14.754 13.925 13.633 14.779 14.011 13.690 — — — — — 18.15 16.72 17.43189 J063118.43+045440.1 14.932 14.086 13.652 14.942 14.113 13.704 — — — — — 18.48 17.27 17.66190 J063204.46+045826.1 14.885 13.959 13.706 14.894 14.126 13.790 13.337 13.190 13.087 12.550 — 18.12 16.85 17.37191 J063216.16+045920.0 14.761 13.856 13.535 14.685 13.862 13.446 13.077 12.803 12.436 11.524 7.253 17.87 16.62 17.37192 J063156.86+045514.7 14.639 13.802 13.509 14.645 13.873 13.541 — — — — — 18.22 16.75 17.49193 J063154.92+045136.1 15.152 14.241 14.037 15.166 14.324 13.967 — — — — — 18.26 17.00 17.18194 J063230.12+045522.1 15.221 14.120 13.594 15.342 14.297 13.563 12.666 12.473 12.129 11.649 9.101 18.61 17.24 17.48195 J063159.29+045137.5 15.057 14.254 14.002 15.104 14.344 14.016 — — — — — 17.97 16.75 17.50196 J063139.87+045639.1 15.053 14.099 13.615 15.086 14.182 13.693 12.894 12.675 12.557 12.431 — 18.12 16.97 17.00197 J063203.08+050134.8 — — — 15.115 14.204 13.626 13.038 12.731 12.296 11.431 7.793 18.42 17.15 17.30198 J063206.98+044803.7 15.148 14.327 14.068 15.198 14.386 14.094 — — — — — 18.35 17.05 17.66199 J063119.47+045309.6 14.828 13.963 13.574 14.851 14.011 13.699 — — — — — 18.29 16.86 17.55200 J063158.91+045743.0 15.307 14.407 13.995 15.176 14.380 13.983 13.565 13.369 12.975 12.229 — 18.31 17.03 17.65201 J063201.50+045502.2 15.170 14.232 13.953 15.187 14.417 14.109 — — — — — 18.13 16.88 17.46202 J063142.58+045256.1 14.717 13.801 13.523 14.684 13.915 13.482 12.477 12.029 11.510 10.717 8.332 18.24 16.69 17.31203 J063227.50+045251.3 14.791 13.810 13.291 14.810 13.927 13.361 12.506 12.305 11.828 11.318 8.036 17.95 16.72 16.88204 J063158.89+045811.0 15.092 14.188 13.741 15.016 14.181 13.673 12.995 12.618 12.015 11.079 — 18.22 17.07 16.92205 J063220.33+045320.7 — — — 16.371 15.790 15.621 — — — — — 18.57 17.65 17.78206 J063205.07+045226.7 14.898 14.070 13.917 14.880 14.110 13.711 13.429 13.320 13.209 12.671 9.495 18.31 16.85 17.36207 J063235.67+044745.8 16.015 14.689 13.978 15.453 14.280 13.573 12.815 12.250 11.677 10.606 7.075 — — —208 J063130.72+045214.9 15.295 14.317 13.909 15.249 14.484 14.120 13.476 13.182 13.092 12.017 8.947 18.53 17.18 17.93209 J063151.55+044727.9 15.185 14.235 13.511 15.253 14.222 13.510 12.406 11.785 11.306 10.358 7.449 18.71 17.28 17.45210 J063152.20+045240.0 15.234 14.430 13.965 15.269 14.482 14.094 13.530 13.158 12.833 11.995 — 18.83 17.34 17.94 c (cid:13) , 1–, 1– ?? G. Michalska
Star Name
J H K S J H K [3 .
6] [4 .
5] [5 .
8] [8 .
0] [24] r i H α mag mag mag mag mag mag mag mag mag mag mag mag mag mag211 J063132.86+045949.4 14.692 13.605 12.884 14.831 13.623 12.586 11.782 11.281 11.074 10.411 7.183 17.53 16.46 17.04212 J063224.01+045659.1 14.971 14.072 13.710 14.895 14.096 13.721 13.190 12.786 12.508 11.833 — 18.30 16.94 17.21213 J063231.91+045109.0 15.632 14.511 13.928 15.446 14.433 13.815 13.146 12.828 12.641 12.037 8.787 18.80 17.41 17.78214 J063222.70+045808.2 15.048 14.198 13.645 15.040 14.213 13.630 12.673 12.296 12.020 11.294 7.954 18.67 17.26 17.58215 J063129.84+045110.6 15.015 13.671 12.738 14.962 13.799 12.645 11.434 10.849 10.390 9.858 6.408 19.13 17.61 17.46216 J063125.45+044930.9 15.345 14.550 14.154 15.206 14.393 13.981 13.424 13.167 12.756 12.007 — 18.84 17.45 17.80217 J063147.36+044943.6 — — — 15.631 14.849 14.562 — — — — — 18.95 17.59 18.21218 J063210.36+045205.8 15.246 14.210 13.833 15.127 14.188 13.635 12.966 12.623 12.234 11.533 9.052 18.64 17.14 17.66219 J063159.35+044954.9 15.098 14.160 13.819 15.317 14.441 13.968 13.398 13.154 12.654 12.137 — 18.77 17.41 17.89220 J063158.73+045346.8 15.676 14.596 14.014 15.615 14.666 14.110 13.389 13.171 12.940 12.520 — 18.99 17.49 18.04221 J063129.40+045034.8 15.592 14.708 14.524 15.642 14.889 14.560 — — — — — 19.45 17.88 18.83222 J063231.50+045453.2 15.803 14.754 14.115 15.686 14.751 14.018 13.059 12.606 12.599 12.284 — 18.76 17.80 16.72223 J063232.66+045701.0 15.437 14.670 14.346 15.452 14.702 14.341 14.166 13.750 13.465 12.783 — 19.67 17.65 18.39224 J063136.58+050515.3 14.963 13.909 13.352 14.874 14.010 13.352 — — — — — 19.13 17.20 17.80225 J063208.95+050151.3 — — — 15.208 14.300 13.794 — — — — — — — —226 J063157.57+045339.0 15.458 14.236 13.682 15.555 14.477 13.819 12.786 12.435 12.041 11.019 — 18.33 16.95 17.62227 J063156.58+045951.4 — — — 15.546 14.771 14.449 — — — — — — — —228 J063223.92+045420.9 15.729 14.817 14.505 15.820 14.977 14.412 13.802 13.651 13.269 12.451 — 19.16 17.81 17.42229 J063143.35+045422.9 15.681 14.541 14.115 15.881 14.983 14.313 13.340 12.973 12.878 12.333 8.816 19.65 18.16 18.66230 J063132.47+050605.6 15.521 14.313 13.610 15.017 14.195 13.583 — — — — — 19.59 17.67 17.98231 J063141.05+045419.8 15.119 14.184 13.765 15.715 14.768 14.024 12.998 12.679 12.330 11.334 — 19.79 17.95 18.78232 J063158.09+045414.9 16.183 14.676 13.719 15.981 14.687 13.707 12.477 11.986 11.488 10.882 8.869 — — —233 J063148.53+050407.2 15.631 14.840 14.229 15.956 15.110 14.548 14.097 13.897 13.686 12.956 9.021 19.34 17.70 18.27234 J063155.47+050054.1 15.802 14.731 14.218 17.567 15.391 14.548 13.238 12.860 12.560 12.031 — 18.91 17.68 17.21235 J063159.68+050627.2 15.255 14.223 13.831 15.335 14.418 13.868 — — — — — 19.68 17.78 18.71236 J063230.20+045401.2 15.550 14.586 13.858 16.199 15.033 14.001 12.760 12.289 11.905 11.308 7.806 — — —237 J063149.00+045547.0 15.626 14.726 14.111 15.598 14.818 14.333 13.808 13.465 13.183 12.442 — — — —238 J063203.65+045952.1 — — — 15.650 14.755 14.151 13.639 13.176 12.822 12.300 — — — —239 J063138.33+050256.5 15.284 14.229 13.665 15.281 14.345 13.640 12.861 12.543 12.154 11.459 — 19.75 17.73 18.38240 J063219.28+045629.4 — — — 16.325 15.495 14.984 — — — — — 19.73 18.37 17.59241 J063207.16+045514.4 — — — 16.120 15.231 14.658 14.444 14.033 13.752 12.758 9.224 — — —242 J063128.39+045035.1 16.038 15.049 14.361 16.009 15.053 14.250 13.198 12.688 12.127 11.468 8.130 — — —243 J063211.98+050030.9 — — — 15.460 14.286 13.403 13.285 12.081 11.079 9.951 6.449 19.56 18.57 18.56244 J063219.98+045748.3 — — — 16.182 15.293 14.618 13.802 13.329 13.099 12.733 — — — —245 J063228.81+045255.9 — — — 16.086 15.234 14.743 14.195 13.905 13.566 13.154 — — — — c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A1.
Phase diagrams of B (blue), V (green) and I (red) observations of other periodic variables found in observed field of NGC 2244 (seeSect. 3.3).c (cid:13) , 1–, 1–
Phase diagrams of B (blue), V (green) and I (red) observations of other periodic variables found in observed field of NGC 2244 (seeSect. 3.3).c (cid:13) , 1–, 1– ?? G. Michalska
Figure A1 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2.
Light curves of B (blue), V (green) and I (red) observations of irregular variables found in observed field of NGC 2244(see Sect.3.4).c (cid:13) , 1–, 1–
Light curves of B (blue), V (green) and I (red) observations of irregular variables found in observed field of NGC 2244(see Sect.3.4).c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1– ?? G. Michalska
Figure A2 – continued c (cid:13) , 1– ?? ariable Stars in Young Open Cluster NGC 2244 Figure A2 – continued c (cid:13) , 1–, 1–