A Variable Star Census in a Perseus Field
T. Pasternacki, Sz. Csizmadia, J. Cabrera, P. Eigmueller, A. Erikson, T. Fruth, P. von Paris, H. Rauer, R. Titz, J. Eisloeffel, A. Hatzes, M. Boer, G. Tournois, P. Kabath, P. Hedelt, H. Voss
aa r X i v : . [ a s t r o - ph . GA ] S e p Variable Star Census in a Perseus Field
T. Pasternacki, Sz. Csizmadia, J. Cabrera, P. Eigm¨uller , A. Erikson, T. Fruth, P. vonParis, H. Rauer , R. Titz Deutsches Zentrum f¨ur Luft- und Raumfahrt, Institut f¨ur Planetenforschung, Rutherfordstraße 2, 12489Berlin, Germany [email protected]
J. Eisl¨offel, A. Hatzes
Th¨uringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
M. Boer, G. Tournois
Observatoire de Haute Provence, St. Michel-l’Observatoire 04870, France
P. Kabath
European Southern Observatory, Alonso de C´ordova 3107, Vitacura, Casilla 19001, Santiago Chile
P. Hedelt CNRS, UMR 5804, Laboratoire d’Astrophysique de Bordeaux, 2 rue de l’Observatoire, BP 89, F-33271Floirac Cedex, France and
H. Voss
Universitat de Barcelona, Departament d’Astronomia i Meteorologia, Marti i Franqu`es 1, E-08028Barcelona, Spain
ABSTRACT
The Berlin Exoplanet Search Telescope (BEST) is a small-aperture, wide-field telescope ded-icated to time-series photometric observations. During an initial commissioning phase at theTh¨uringer Landessternwarte Tautenburg (TLS), Germany, and subsequent operations at the Ob-servatoire de Haute-Provence (OHP), France, a 10-square-degree circumpolar field close to thegalactic plane centered at ( α, δ ) = (02 h m s , +52 ◦ ′ ′′ ) ( J .
0) was observed betweenAugust 2001 and December 2006 during 52 nights. From the 32 ,
129 stars observed a subsampleof 145 stars with clear stellar variability was detected out of which 125 are newly identified vari-able objects. For five bright objects the system parameters were derived by modelling the lightcurve.
Subject headings: data analysis — stars: variable: general — binaries:eclipsing — Cepheids — δ Scuti— techniques: photometric . Introduction The Berlin Exoplanet Search Telescope (BEST)is a small-aperture, wide-field telescope dedi-cated to time-series photometric observations.At present BEST is located at Observatoire deHaute-Provence, France (OHP) and is remotelycontrolled from Berlin (Rauer et al. 2004, 2010).From 2001 to 2003 BEST was located at theTh¨uringer Landessternwarte (TLS), Germany, fora commission phase. Primarily built-up to pro-vide ground-based support to the CoRoT spacemission (Baglin et al 2006), BEST offers the greatpossibility for detection and examination of newvariable stars due to its high-precision stellar pho-tometry.Based on photometric observations of eclipsingbinaries, constraints can be set on their orbitalinclination and relative radii. Together with ra-dial velocity measurements it is possible to deter-mine absolute system parameters. Only with thisknowledge details of the structure and evolutionof the observed system becomes available.The present paper describes the observations ofa selected target field located in Perseus. Obser-vations were done between 2001 and 2003 fromthe TLS site and between 2005 and 2006 fromthe OHP site. Previously published results basedon BEST observations in support of the CoRoTspace mission can be found in Karoff et al. (2007);Kabath et al. (2007, 2008); Rauer et al. (2010).
2. Telescope and observations
BEST is a f / . × . ◦ × . ◦ and the re-sulting pixel scale is 5 . Th¨uringer Landessternwarte Tautenburg, Sternwarte5, 07778 Tautenburg, Germany Technische Universit¨at Berlin, Zentrum f¨ur Astronomieund Astrophysik, Hardenbergstraße 36, 10623 Berlin, Ger-many Observatoire Aquitain des Sciences de l’Univers, 2 ruede l’Observatoire, BP 89, F-33271 Floirac Cedex, France
This paper deals with the variable star census ina target field located in the constellation of Perseuscentered on the coordinates: α ( J .
0) = 02 h m s δ ( J .
0) = +52 ◦ ′ ′′ . The target field was observed with BEST fromthe TLS site between 2001 August 15 to 2003March 13 during 25 nights for a total of 70 hours.After the relocation of BEST to OHP in 2004 thesame field was observed between 2005 November 7and 2006 December 20 during 27 nights for a totalof 87 hours.The observational sequence consisted of anequal number of images with 40, 120 and 240 sexposure time, followed by a bias and dark im-age after each second run. Additionally, flat andbias images were acquired at the beginning of thenight. Here we only present data with 240 s expo-sure time, corresponding to 1036 frames in total,566 from TLS and 473 from OHP. From the totaldata set we were able to detect and obtain lightcurves for around 32 ,
129 stars within a magni-tude range between 11 to 17 mag. The data setis available to the scientific community upon re-quest .
3. Data Processing3.1. Reduction pipeline
The acquired data are processed with an auto-mated pipeline combining experience from earlierreductions within the BEST project (Kabath et al.2007; Karoff et al. 2007; Kabath et al. 2008, 2009a,b;Rauer et al. 2010).The first step comprises bias, dark and flat-fieldcorrection for every frame. In order to achievehigh precision photometry we use image subtrac-tion (Alard 2000) to detect brightness variationsclose to the noise limit. After shifting every frameto a common image coordinate system, a set of tenframes with the best photometric quality is com-bined to a reference image. Thereafter, the refer-ence image is transformed to every scientific imageby convolution with a space-varying kernel. Then,the scientific images are subtracted from the fitted contact by email: [email protected] Bad weather conditions and systematic offsetsbetween different nights can affect the photomet-ric accuracy of the BEST system. To assess thephotometric quality in single nights the standarddeviation ( σ i ) is calculated for the light curves ofevery star i . We found 22 out of 52 nights in whichmore than 2 ,
000 stellar light curves have a σ i lessthan 1 % in the magnitude range between 10 . σ < σ i of the lightcurves are plotted against the stellar magnitudefor the whole data set of 52 nights. Also markedare the known and newly detected variable starspresented in this paper. A comparison betweenboth groups shows that the present survey goesdeeper in magnitude then the previous ones. Theknown variables are more dominant in the brightregime with large σ i -values, whereas the newly de-tected variables are homogeneously distributed inmagnitude and σ i .Fig. 1.— Standard deviations σ i vs. magnitudefor the whole data set of 52 nights. Known vari-ables are marked with blue crosses and new detec-tions are marked with a red dot. See the electronicedition of the Journal for a color version of this fig-ure. For identification of potential stellar variabilitywe use variability index J introduced by Stetson(1996) with modified weighting factors accordingto Zhang et al. (2003). The distribution of thecalculated J -indices versus magnitude is shownin Fig. 2. Based on the experience acquired inthe analysis of previous fields characterized withBEST a limiting value of J > . ,
000 stars which were subsequently examinedfor periodic variability using the Analysis-of-Variance (AoV) algorithm (Schwarzenberg-Czerny1996). Due to the size of the data set at hand, welimited our search to periodic signals between 0.13ig. 2.— Distribution of Stetson’s variability in-dex J vs. magnitude shown for all detected starsin the data set. Red dots denote newly detectedvariable stars with BEST while blue crosses dis-play previously known variable stars. The dashedline marks the lower limit of J = 0 .
4. Results
The variable star census in a Perseus target fieldyielded 145 light curves showing clear variable sig-nals, periodic or aperiodic. Thereof 125 are newlydetected variable objects and 20 were previouslyknown. For newly detected variable stars we useda GCVS-based reduced classification mainly sep-arating in intrinsic and extrinsic variable stars(Samus et al. 2009).Intrinsic variables are stars whose variabilityis caused by changing internal stellar propertiesleading to a change in luminosity, e.g pulsation.We used the subgroups δ Scuti (DSCT), γ Do-radus (GDOR), δ Cephei (DCEP) and RR Lyrae Table 1: Statistical Overview for all detected vari-able stars. Values in parenthesis state the numberof new detections.observed stars 32 , J > . , Intrinsic
DCEP 1 (1)DSCT 31 (30)RRLYR 2 (2)
Extrinsic
EA 24 (21)EB 6 (6)EW 45 (42)ACV 5 (5)ELL 5 (5)SP 1 (1)other 25 (12)
Total variable stars 145 (125 )previously known 20(RRLYR) stars.Extrinsic variables show apparent changes inbrightness due to external processes like eclipses orrotation. Here we use eclipsing binaries type starson the one hand, divided into Algol- (EA), β - (EB)and W Ursae Majoris-type (EW), and the rotat-ing variables on the other hand, divided into el-lipsoidal variables (ELL) and the strong magneticvariables α Canum Venaticorum (ACV). Remain-ing objects for which no assignment is possible areclassified as miscellaneous (MISC).An overview of the total number for every sub-type, split into new and known detections, canbe found in Table 1. The percentage of variablestars in the whole data set of 32 ,
129 stars amountsto 0 .
45 % and is of the same order as in otherphotometric surveys, e.g. ASAS 3 with 0 .
34 % orOGLE II with 0 .
70 % (Eyer & Mowlavi 2008).The catalog of all detected variable stars in thedata set is provided in Table 3. It shows the coor-dinates, R magnitude, period, epoch, amplitude,and variability type for every detected variable ob-ject. Already known objects are marked with flag’k’ and crowded stars are marked with flag ’c’.Crowded in this sense means, that at least twodifferent stars in Table 3 show exactly the same4ig. 3.— Amplitudes of the different kinds of vari-able stars in the observed field as a function of pe-riod. See the electronic edition of the Journal fora color version of this figure.period (e.g. F2 03278 and F2 03319). These ob-jects are below the angular resolution limit of ourCCD camera and have overlapping Point-Spread-Functions (PSFs). The real source of variabilityfor those objects cannot be determined from ourdata set.In addition, the reader should be aware of thecontamination problem when using the measuredamplitudes in Table 3. These are real, if no con-taminating objects lie within a radius of 27 . .
07 to 10 days, whereas the ampli-tude range starts at 0 .
015 mag and ends at 1 mag.Note that the shorter the period the smaller thedetected amplitudes because of the increase of thesignal-to-noise ratio.In the following paragraphs we discuss the typesof the variable stars detected in our data set. Al-ready known variable stars are discussed in Section4.1 and the newly detected extrinsic and intrinsicvariable stars in Section 4.2 and 4.3, respectively.We further investigated the most interestingand promising objects among the binary detec- tions. Thus, if the whole phase range of anobject is covered and if there are enough datapoints during the eclipses, we are able to de-rive system parameters for eclipsing binaries.For these cases we modelled the light curveswith a binary star light curve modelling code(Csizmadia et al. 2009), which assumes Roche-geometry and provides results comparable withthe model of Wilson & Devinney (1971). The so-lutions from this model are optimized via a geneticalgorithm as described in Geem et al. (2001).Among the modelled EW-type variables wefurther distinguish between A-subtype and W-subtype systems following Binnendijk (1965) andCsizmadia & Klagyivik (2004a). In an A-subtypesystem the hotter star is the more massive com-ponent and it is vice versa for members of a W-subtype system.
The stars observed with BEST are cross-checked with the Variable Star Index (VSX) ofthe American Association of Variable Star Ob-servers and with the General Catalog of VariableStars (GCVS) (Samus et al. 2009). Within theobserved target field, in total 26 previously knownvariable stars could be found according to thesecatalogs. For 20 of these stars we could confirmthe previously detected stellar variability. The re-maining six cases were too bright to be observedwith BEST and consequently were saturated inthe acquired data set.In the variable star catalog (Table 3) all pre-viously known objects are marked with flag ’k’.For the following 12 long periodic or irregularknown variables we are only able to confirm thevariability: EF Per, EE Per, EH Per, V0670Per, V0726 Per, V0727, NSVS J0243375+530503,NSVS J0236346+524133, SAVS 023628+521630,NSVS J0242125+513436, NSV 935, and NSVSJ0235501+533958. Confirmation of previously as-signed stellar variability classes was only possiblefor short periodic objects due to the BEST dutycycle. Hereafter we discuss the remaining eightcases of previously known and short periodic vari-ables individually. f = Ω L − ΩΩ L − Ω L ,where L and L are the Lagrange-points, and Ω is the dimensionless surface potential, see e.g. Kopal (1978). catalog ID DV Per NSVS 1926064 NSVS 1913469 - NSVS 4052900BEST ID F2 02633 F2 04262 F2 10496 F2 10966 F2 20731 Measured parameters
Magnitude RB [mag] 13 .
68 11 .
50 11 .
25 12 .
34 13 . P [d] 1 . . . . . T . . . . . A [mag] 0 .
17 0 .
40 0 .
19 0 .
12 0 . J − K .
255 0 .
377 0 .
345 0 .
254 0 . System parameters
Grav. darkening g g .
32 (fixed) 0 .
32 (fixed) 0 .
32 (fixed) 1 . .
32 (fixed)Bol. limb dark. (pri, sec) 0 . . . . . A A . .
50 (fixed) 0 .
50 (fixed) 1 . .
50 (fixed)Mass Ratio q . . ± .
007 0 . ± .
02 0 . ± .
05 0 . ± . T ±
120 5130 ±
180 5630 ±
180 6660 ±
380 5764 ± T i [ ◦ ] 85 . ± . . ± . . ± .
09 50 . ± .
54 85 . ± . f − . ± . f f f f f f f f f − . ± .
098 0 . ± .
020 0 . ± .
018 0 . ± .
037 0 . ± . . . ± .
06 0 . ± .
09 0 . ± .
70 0 . ± . . . ± .
05 0 . ± .
17 0 . ± .
20 0 . ± . pri . . . . f f sec . . . . . Stellar fractional radii
Primary
R1 (Pole) 0 . . . . . . . . . . . . . . Secondary
R2 (Pole) 0 . . . . . . . . . . . . . . . . The variability of DV Persei was discovered byHoffmeister (1944). He reported an orbital pe-riod of P = 0 . A pri =0 . A sec = 0 . . P = 1 . . q = 1 . J and K we estimated thetemperature of the primary star to be 6300 K andkept it fixed at this value. Remaining parame-ters were fixed according to Table 2. The foundsolution suggests a physically plausible detachedconfiguration (Fig. 4 and Table 2).A detailed spectroscopic study to measure thetrue mass ratio as well as multicolor photometryis highly desirable for a further, detailed studyof this system. Combination with radial velocitymeasurements will clearly decide between the oldand newly proposed period value. Furthermore,this detached system with two nearly equal starsin a short period orbit is suitable for testing stellarevolutionary models.6ig. 4.— Light curves of the modelled binary systems F2 2633 (DV Per), F2 04262 (NSVS 1926064),F2 10496 (NSVS 1913469), F2 10966 and F2 20731 (NSVS 4052900). Points represent the measurementsand the red solid line denotes the fit of the light curve solutions. See the electronic edition of the Journalfor a color version of this figure. 7 .1.2. EN Per EN Per (F2 14415 in our data set) is a mod-erately faint ( V = 13 . . . . The variability of the EW-type eclipsing binarystar F2 04262, also known as suspected variablestar NSVS 1926064 (Gettel et al. 2006), is nowconfirmed. We find an identical orbital periodof 0 . . i ≈ ◦ stronglyreduce the degeneracy of possible light curve solu-tions (Ruci´nski 1973).In order to find a light curve solution with theused model (Csizmadia et al. 2009) we fix the tem-perature of the primary at T = 6000 K based onthe period-color-relation of Wang (1994). Table 2shows an overview of the free and fixed parame-ters together with the results. Fig. 4. illustratesthe light curve plus the determined fit. The systemhas a high inclination of (88 ◦ ± ◦ , moderate thirdlight of 13 % coming from a non-resolved star, anda common mass ratio of q = 4 . ± .
11. The sys-tem has a very high fill-out factor of f = 0 . The object NSVS 1913469 (F2 10496) is de-clared as EW in VSX with an amplitude of0 .
31 mag in R1 and a period of 0 . . .
19 mag (Fig. 4). The light curve shows theO’Connell-effect, i.e. the secondary maximum isa bit higher than the primary. In well-studiedcases it was found that EW-type variables showcycle-to-cycle variations due to variable spot sizes,temperatures and distribution (Csizmadia et al.2004b). For further investigation of this effectmulticolor-photometry is needed. The system be-longs to the A-subtype class of contact binaries.There is no clear sign of a total eclipse, sug-gesting that the object is probably a medium-inclination system. Via light curve modelling wefound an inclination of ∼ ◦ . It is a low-degree-of-contact system with a small fill-out factor of f = 0 . L / ( L + L + L ) ≈ .
48, which may originatefrom a nearby, not fully resolved optical compan-ion. This high value of the third light squeezes theamplitude to the observed value and can explainthe large difference in the observed amplitudes.Similary high third light values are common inother EW-binaries, e.g. with a record of L / ( L + L + L ) ≈ .
93 in V758 Cen (Lipari & Sistero1985; Csizmadia & Klagyivik 2004a). The resultsfor NSVS 1913469 are shown in Table 2 and inFig. 4.
This EW-type eclipsing binary star F2 20731belongs to the A-subtype. It has a low fill-out factor of 12 . L / ( L + L ) = 23 %. This light probably comesfrom a nearby companion star, which is not fully8esolved with our pixel scale. The light curveshows total primary eclipse, which is confirmedby the light curve modelling result ( i ≈ ◦ ). Al-though its high inclination makes it interesting forfurther studies, it is moderately faint with 13 . . . The VSX denotes for object NSVS 1910955(F2 13911) a period of 1 . .
81 mag in R1 for this EA-type variablestar. Period and type are confirmed, but the de-termined amplitude differs by a factor of 4.3, sincewe found an amplitude of 0 .
19 mag.VSX denotes variability type DSCT and a pe-riod of 0 . P = 0 . .
08 mag.The object VSX J023706.8+503557 (F2 25347)is declared as a DSCT with 0 . . The majority of the newly detected variablestars are eclipsing binaries with in total 69 de-tected objects. The largest subgroup of the bi-naries are the EW-type stars with 42 new detec-tions. Stars of the EA sub-type amount to 21 newdetections and the smallest subgroup are the semi-detached binaries of sub type EB with 6 represen-tatives.We found 11 newly detected rotating variablestars, split into 5 ACV type, 5 ELL type and 1spotted variable star. Details to these objects can be found in Table 3 and Fig. 5.Below, some cases of special interest are dis-cussed in detail. Among these objects, we wantto emphasize the eccentric binaries F2 00254 andF2 03278. Eccentric eclipsing binaries are key ob-jects to critically check the stellar structure andevolutionary models via the extremely sensitive’apsidal-motion test’ (B¨ohm-Vitense 1992). Only18 adequate systems have been available in a re-cent study (Claret & Gimenez 2010). Discoveriesof new eccentric eclipsing binaries, like this presentcases, help to extend the sample with new possibletargets.
The moderately bright ( R = 13 .
48 mag) objectF2 00254 is a newly discovered Algol-type variablewith a low amplitude of 0 . ϕ = 0 .
48 indicating aneccentric orbit, although it has a relatively shortorbital period for eccentric binaries of 2 .
16 days.From the displacement of the secondary and thelengths of the eclipses one can suspect a small ec-centricity of 0 .
03 with an argument of periastronof 36 ◦ . A low number of measurements duringthe eclipses makes it an unsuitable object for lightcurve modelling. For further investigation the sys-tem requires spectroscopic and radial velocity ob-servations as well as precise timings. The object F2 03278 stands out due to the largedisplaced secondary eclipse at ϕ = 0 .
36. Despiteits relatively short period of 1 . .
24 with an argument of perias-tron of 16 ◦ . The total variation does not exceed0 .
17 mag. It is a bright object with R = 12 . One of these two stars is a short-period Algol-object. They are separated by 18 arcseconds anddue to limits in spatial resolution the light curvesare affecting each other. Thus, it is not clear whichof these two stars is variable. Further studies withhigher angular resolution are needed in order todistinguish between them. We do not carry out a9ight curve modelling of this system since our ob-servational data is not complete enough to decidefor the correct period.The real variable among these two objects hasa considerably short variability period. Eclipsesoccur in every 0.54 days, while most of the Algol-type variables have much larger orbital periods.The duration of the eclipse is 25% of the period,extremely long. This may imply that the orbitalperiod is twice the value published here in reality.If the given period is true, it is a quite importantobject, because EA-type binaries in this periodregime are rare (Paczy´nski et al. 2006).
This EW-type binary is largely contaminatedby a nearby star, not fully resolved by our pixelscale (Fig. 4). The third light was found to belarge with L / ( L + L ) = 0 .
55. The system hasa low inclination of ∼ ◦ and as Ruci´nski (1973)pointed out the determination of mass ratio byphotometry in the case of low-inclination contactbinaries is quite difficult. This fact and the lowquality photometry caused by the nearby disturb-ing companion make the results uncertain. Forinstance the mass ratio can be constrained onlyto be q = 3 . ± .
59. The larger star is the hot-ter one, so the system belongs to the A-subtypeof the contact binaries. Results of the light curvemodelling are given in Table 2 and Fig. 4.
The interesting feature of this Algol-type vari-able is the linearly decreasing brightness betweenprimary and secondary minimum, followed by anew increase from secondary to primary. This in-dicates a relatively strong reflection effect. Thesystem is also slightly eccentric because the sec-ondary is at phase ϕ = 0 . P = 1 .
25 days).
This object is a high amplitude EA-type starwhich shows variations of 1 .
01 mag. Its periodof 1 .
96 days is close to two days and possibly ex-plains, why this variability could escape from dis-covery until today despite its large amplitude.It is conspicuous, that the few observationsof the primary minimum are not matching each other. This may suggest some period variation,which is a common effect in semi-detached clas-sical Algol-system. The light curve also suggests,that there can be out-of-eclipse variations causedeither by pulsation or gas-streams in the system.The system evidently requires more photometricstudies.
The β Lyrae-type eclipsing variable F2 21539has an orbital period close to one day ( P ≈ . The second largest group are the pulsating starswith 39 detected objects, out of which 37 are newdetections. The subgroup of DSCT-stars is mostdominant here with 33 new detections. Remainingobjects are one Cepheid and three RR Lyrae-typestarsThe most intriguing member of the intrinsicvariables is the object F2 09743, which is a typi-cal mono-periodic δ Scuti-type star. With a shortperiod of 0 .
18 days, a high amplitude of 0 .
24 magand a brightness of 12 .
85 mag this object is afavourable target for future studies. Note, thatmost of the DSCT stars show some light curvemodulations, while this object featured a very sta-ble light curve during the 5 years of observationsbetween 2001-2006.
5. Summary
We observed with BEST a 3 . ◦ × . ◦ fieldin the constellation Perseus in 52 nights between2001 August and 2006 December from the loca-tions TLS and OHP. In a sample of 32 ,
129 lightcurves we detected 145 variable objects, out ofwhich 125 are new detections.10ariability of the known variables DV, EF, EN,EE, EH, V670, V726, and V727 Persei is con-firmed. We present an updated period value andthe first light curve parameter estimation for DVPer, which seems to be a suitable object for stel-lar evolutionary studies. The period for EN Peris confirmed. For the remaining 6 known variableswe are just able to confirm their variability. State-ments about type, period, and amplitude are notpossible due to the poor phase coverage.Furthermore, the variability of 12 previouslysuspected variables is confirmed. For six of themwe are able to confirm the type but find slightlydifferent periods and occasionally totally differentamplitudes of variation. The remaining six casesare confirmed as clearly variable objects, but weare not able to determine periods for this onesdue to long- or semi-periodicity. For 4 stars withknown variability the system parameters were cal-culated by modelling the light curve for the firsttime.Among the 125 new detected variables 36 newpulsating variables, 69 new eclipsing binaries and12 other extrinsic variable stars were found. Thepercentage of variable objects in the BEST dataset is 0 .
45 % and thus comparable to other photo-metric wide-field surveys.
Acknowledgements
We thank the Observatoirede Haute Provence for great support of the BESTsurvey. This publication makes use of data prod-ucts SIMBAD, 2MASS and USNO-A2.0 as well asthe AAVSO variable star index. We are also grate-ful to the observers Michael Weiler, Tino Wiese,Susanne Hoffmann, Christopher Carl and MartinDentel.
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This 2-column preprint was prepared with the AAS L A TEXmacros v5.2. able 3Variable Stars detected in the observed BEST field with coordinates, magnitude, period,epoch, amplitude, and variability type. Stars affected by crowding are flagged with c.The flag k denotes previously known objects and their ID from VSX or GCVS can befound in the last column. The Epoch T is given in reduced Julian date [rJD] in respectto T = 2 , , . . It denotes the first minimum in the light curve. (This table is availablein its entirety in machine-readable and Virtual observatory (VO) forms in the onlinejournal. A portion is shown here for guidance regarding its form and content.) BEST ID flag 2MASS ID α ( J . δ ( J .
0) R B [mag] T [rJD] P [d] A [mag] Type Other namesF2 00026 c 02304181+5329285 02 h m . s ◦ ′ .
9” 14.40 2196.541 0 . ± . . ± .
09 EAF2 00038 c 02304450+5329209 02 h m . s ◦ ′ .
5” 14.63 2196.538 0 . ± . . ± . h m . s ◦ ′ .
4” 10.93 2280.534 5 . ± .
004 0 . ± . h m . s ◦ ′ .
8” 13.48 2197.066 2 . ± . . ± .
05 EAF2 00339 c 02432992+5329386 02 h m . s ◦ ′ .
5” 13.97 2196.736 0 . ± . . ± .
05 EWF2 00359 c 02433226+5329253 02 h m . s ◦ ′ .
3” 14.02 2196.735 0 . ± . . ± .
05 EWF2 01065 02364668+5322516 02 h m . s ◦ ′ .
1” 12.70 2197.098 7 . ± .
003 0 . ± .
03 EAF2 01655 c 02450572+5319123 02 h m . s ◦ ′ .
9” 14.72 2195.597 0 . ± . . ± .
06 EW13