Antisolar differential rotation with surface lithium enrichment on the single K-giant V1192 Orionis
Zs. Kővári, K. G. Strassmeier, T. A. Carroll, K. Oláh, L. Kriskovics, E. Kővári, O. Kovács, K. Vida, T. Granzer, M. Weber
AAstronomy & Astrophysics manuscript no. kovarietal_langed__31100_corr c (cid:13)
ESO 2018September 11, 2018
Antisolar differential rotation with surface lithium enrichment onthe single K-giant V1192 Ori (cid:63)
Zs. K˝ovári , K. G. Strassmeier , T. A. Carroll , K. Oláh , L. Kriskovics , E. K˝ovári , O. Kovács , , K. Vida ,T. Granzer , and M. Weber Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege út15-17., H-1121, Budapest, Hungarye-mail: [email protected] Leibniz-Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam, Germany Eötvös University, Department of Astronomy, Pf. 32., H-1518, Budapest, HungaryReceived ; accepted
ABSTRACT
Context.
Stars with about 1 − Aims.
The single rapidly rotating K-giant V1192 Ori is revisited to determine its surface di ff erential rotation, lithium abundance, andbasic stellar properties such as a precise rotation period. The aim is to independently verify the antisolar di ff erential rotation of thestar and possibly find a connection to the surface lithium abundance. Methods.
We applied time-series Doppler imaging to a new multi-epoch data set. Altogether we reconstructed 11 Doppler imagesfrom spectroscopic data collected with the STELLA robotic telescope between 2007–2016. We used our inversion code iMap toreconstruct all stellar surface maps. We extracted the di ff erential rotation from these images by tracing systematic spot migration as afunction of stellar latitude from consecutive image cross-correlations. Results.
The position of V1192 Ori in the Hertzsprung-Russell diagram suggests that the star is in the helium core-burning phase justleaving the RGB bump. We measure A (Li) NLTE = .
27, i.e. a value close to the anticipated transition value of 1.5 from Li-normal toLi-rich giants. Doppler images reveal extended dark areas arranged quasi-evenly along an equatorial belt. No cool polar spot is foundduring the investigated epoch. Spot displacements clearly suggest antisolar surface di ff erential rotation with α = − . ± .
02 shearcoe ffi cient. Conclusions.
The surface Li enrichment and the peculiar surface rotation pattern may indicate a common origin.
Key words. stars: activity – stars: imaging – stars: late-type – stars: starspots – stars: individual: V1192 Ori
1. Introduction
Stellar magnetic activity manifests itself in cool starspots on thestellar surface and is strongly related to rapid rotation. Althoughmost of the stellar angular momentum is supposed to be trans-ferred to its environment by a wind and consequent magneticbraking on the main sequence, there are examples of evolved redgiant branch (RGB) stars that are still rapidly rotating and mag-netically active. Most of these are members of close binary sys-tems in which tidal forces maintain fast rotation. Rapidly rotat-ing single giants remain a challenge for angular-momentum evo-lution theories. There are scenarios that allow a star to keep itsangular momentum after the main sequence, such as enhancedmixing and dredge-up episodes (Simon & Drake 1989; Char-bonnel & Lagarde 2010) or planet engulfment (Privitera et al.2016b).After the main sequence, RGB stars of about 1 − Send o ff print requests to : Zs. K˝ovári (cid:63) Based on data obtained with the STELLA robotic observatory inTenerife, an AIP facility jointly operated by AIP and IAC.
The mixing of the envelope material with the hotter layers belowinfer the decay of light elements. This short evolutionary periodcalled the first dredge up is responsible for the dilution of thesurface lithium. Despite the expected low lithium abundance, ahandful of low-mass stars in this evolutionary state show lithiumenrichment on their surfaces. For intermediate mass ( ≈ − M (cid:12) )stars at the asymptotic giant branch (AGB), the Cameron–Fowlermechanism (Cameron & Fowler 1971) followed by a transportof the Li to cooler regions can plausibly explain the lithiumexcess. On the other hand, for lower masses at the RGB thismechanism may not work and other non-standard extra mix-ing processes are required (cf. Sackmann & Boothroyd 1992;Charbonnel & Lagarde 2010). In turn, cool-bottom processes(Wasserburg et al. 1995; Sackmann & Boothroyd 1999) belowthe convection zone may also be capable for transporting ma-terial to layers hot enough for the Cameron–Fowler mechanismand then returning to the convection zone. An alternative evolu-tionary model was proposed by de La Reza et al. (1996) in whichbasically every low-mass K-giant undergoes a short ( ≈ yr) Li-rich phase on the RGB (see also de la Reza et al. 1997; Kirbyet al. 2016). Extra non-axisymmetric mixing that leads to aninhomogeneous super-granulation pattern on the surface in the Article number, page 1 of 14 a r X i v : . [ a s t r o - ph . S R ] A ug & A proofs: manuscript no. kovarietal_langed__31100_corr form of large cool and warm features was invoked to explainsuper-meteoritic Li abundances in Strassmeier et al. (2015).So far, di ff erential rotation is found to be solar type for main-sequence stars, but giant stars can exhibit antisolar di ff erentialrotation, i.e. the equator rotates more slowly than the poles (Vogt& Hatzes 1991; Strassmeier et al. 2003; K˝ovári et al. 2015,etc.). Theoretically, this phenomenon is induced and maintainedby strong meridional circulation (Kitchatinov & Rüdiger 2004).Aurnou et al. (2007) proposed that strong mixing by turbulentconvection would be the primary agent for angular momentumequilibration and thus antisolar di ff erential rotation. Detailed nu-merical simulations by, for example Käpylä et al. (2014) andGastine et al. (2014), suggest that rapidly rotating stars with asmall Rossby number yield solar-like di ff erential rotation, whileweakly rotating stars with large Rossby numbers may sustain an-tisolar di ff erential rotation. On the other hand, only three singlerapidly rotating giants are known so far to exhibit antisolar dif-ferential rotation, namely DI Psc, DP CVn (K˝ovári et al. 2013),and V1192 Ori (Strassmeier et al. 2003, the star revisited in thispaper).Interestingly, these stars are listed among the very few fast-rotating RGB stars with unusually high surface lithium abun-dances (see Table 1 in Charbonnel & Balachandran 2000), im-plying a possible connection between the antisolar di ff erentialrotation profile and the enhanced surface lithium (Kriskovicset al. 2014). We posit whether it is possible that a yet-unknownmixing mechanism responsible for the lithium enrichment caneventually also alter the surface di ff erential rotation profile to beantisolar. We believe that such fast-rotating, single, RGB starsprovide a good opportunity to investigate the relationship be-tween activity, rotation, di ff erential rotation, and surface lithiumabundance.In this paper, we present a time-series Doppler imagingstudy of the single rapidly rotating ( P rot ≈
28 days) K-giantV1192 Ori ( = HD 31993), based on spectroscopic observationsfrom the STELLA robotic observatory in Tenerife (Strassmeieret al. 2010). The star was found to have strong Ca ii H&K emis-sion and was classified as a K2 giant (Bidelman & MacConnell1973; Fekel et al. 1986; Strassmeier et al. 1990) with an unusu-ally high v sin i value of 31 km s − (see also Fekel 1997; Fekel& Balachandran 1993). V1192 Ori was catalogued as Li-rich ac-cording to its lithium abundance, which is substantially largerthan expected for an ordinary K giant (Fekel 1988). The non-local thermodynamic equlibrium (NLTE) lithium abundance forV1192 Ori was measured as A (Li) = . ± . A (Li) ≥ . A (Li) of 1.7 assuming local thermodynamic equlibrium(LTE), and 1.8 with NLTE correction. More recently, Rebullet al. (2015) quoted the star as Li-normal with A (Li) = . Einstein and ROSAT surveys (Gioia et al. 1990; Voges et al.1999, respectively). International Ultraviolet Explorer (IUE) ob-servations revealed an active UV chromosphere (Fekel & Bal-achandran 1993) in accordance with the photospheric light vari-ability (Strassmeier et al. 1997a, 1999), which is attributed tostellar rotation and cool starspots. According to the Zeeman sig-natures detected by Aurière et al. (2015), V1192 Ori possesses astrong surface magnetic field that is likely produced by an α Ω -type dynamo. The star is also listed in the IRAS (Gezari et al. 1999) and 2MASS (Cutri et al. 2003) infrared point source cata-logues.The first comprehensive photometric and spectroscopicstudy of V1192 Ori was carried out by (Strassmeier et al. 2003,hereafter Paper I). A rotational period of ≈
26 days was derivedfrom the photometric variability which, together with v sin i of32 km s − , suggested a minimum radius of ≈ R (cid:12) that is con-sistent with the K2 giant classification. The comparison of theposition of V1192 Ori in the Hertzsprung-Russell (H-R) diagramwith feasible evolutionary tracks yielded a mass determination of1.9 M (cid:12) . In Paper I two Doppler images were presented for con-secutive rotation periods showing cool starspots mostly at low tomid-latitudes. Surface di ff erential rotation was investigated bycross-correlating the subsequent maps and yielded antisolar dif-ferential rotation. Such observations are relevant constraints fordynamo theory, hence their reliability is of great consequence.Therefore, we revisit V1192 Ori and carry out a new, more de-tailed Doppler-imaging study from new high-quality spectro-scopic data.The paper is organized as follows. In Sect. 2 we describe theobservations and in Sect. 3 provide a more accurate photomet-ric period from the available photometric data. The astrophysicaldata are summarized in Sect. 4, where we also present a redeter-mination of the surface lithium abundance. In Sect. 6, we focuson the time-series Doppler imaging. The results are summarizedand discussed in Sect. 8.
2. Observations
Two data sets for V1192 Ori were obtained. The first part ofthe observations was collected between February 1993–March1997 (JD 2,449,024–2,450,537), while the second part was ob-tained between March 2007–December 2014 (JD 2,454,173–2,457,003). All observations were carried out with the T7(‘Amadeus’) 0.75 m automatic photoelectric telescope (APT) atFairborn Observatory in southern Arizona (Strassmeier et al.1997b), which is currently owned and operated by the Leibniz-Institute for Astrophysics Potsdam (AIP); see Granzer et al.(2001) for more details. The two data sets consist of altogether1312 measurements in Johnson-Cousins V and I C . HD 32191( V = m . ± m . I C = m . ± m . V data are plotted in Fig. 1. A total of 460 high-resolution echelle spectra were recorded withthe 1.2 m STELLA robotic observatory (Strassmeier et al. 2010)at the Izaña Observatory in Tenerife, Spain, between Jan 9, 2007and Feb 3, 2016. The telescope is equipped with the fibre-fed,fixed-format STELLA Echelle Spectrograph (SES). The spectracover the full 3900–8800 Å wavelength range with an averagespectral resolution of R =
55 000. Further details on the perfor-mance of the system and the data reduction procedures can befound in Weber et al. (2008, 2012) and Weber & Strassmeier(2011). Table A.1 in the Appendix gives the log of the SESobservations used for the Doppler reconstructions presented inSect. 6.
Article number, page 2 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori a. -1.10-1.05-1.00-0.95 50000 52000 54000 56000 D e lt a V HJD - 2400000 b. A m p lit ud e Fig. 1. a.
Long-term photometric V data of V1192 Ori observed withthe Amadeus APT. b. Amplitude spectrum (top) and spectral window(bottom) from the Johnson V data obtained between 1993–1997. Thethree most significant period signals are indicated. See text for details.
3. Photometric period
Using the Fourier transformation-based frequency analyser codeMuFrAn (Csubry & Kolláth 2004) we analysed the V data ofV1192 Ori to refine the photometric period. In Paper I, only the1996-1997 APT data were used for the period search, yieldingin principle the correct but ambiguous and uncertain period of25.3 d.The quality of the new photometric data turned out to bevery uneven between the two sets of observations (see Sect. 2.1).We found that the second set from March 2007–December 2014is rather noisy compared to the first set from February 1993–March 1997. Moreover, the rotational variation of V1192 Ori hasusually low amplitude. Therefore, we used only the first datapart for the period analysis. The resulting amplitude spectrum isshown in Fig. 1. For the refinement of the period we took thethree highest peaks and perform a multi-periodic fit. From thisthe highest amplitude belongs to the 28.3 d period (middle tickmark in the top panel of Fig. 1). We confirmed this period byconsecutively pre-whitening with the three periods. Finally, wesettled on P phot = . ± .
02 d. The other significant periodsdenoted by the other tick marks are 27.59 d and 30.06 d. Owingto the crosstalk between the neighbouring peaks, it is not evi-dent that the highest amplitude peak corresponds to the middletick. Therefore, in Table 1 we listed the frequencies, amplitudesand residuals of 1-, 2-, 3- and 4-component Fourier-fits carriedout subsequently. The residuals decrease significantly until the3-component fit, however, introducing the 4th component yieldsonly marginal improvement. In the 3- and 4-component fits thehighest amplitudes correspond to ≈ / d, i.e. ≈ Table 1.
Multi-component Fourier-fit parameters
Frequency Amplitude Residual Residual[c / d] di ff erence f = f = f = f = f = f = f = f = f = f = ff erential rotation, we obtained a surface shear parameter ∆ P / P of ≈ ff erential rotation is solartype or antisolar, but see Reinhold & Arlt (2015) for long-termspace photometry.The new photometric period is longer by ≈
10% compared tothat from Paper I and is based on a data set that is roughly fourtimes longer. The 2f harmonic of 13.9 d in Paper I also indicateda longer period of around 28 d. The second, more noisy part ofthe data between March 2007–December 2014 yields a 31.8 dperiod but with a very low significance. Putting together all theavailable photometric data results in an ≈
28 d period. Therefore,we accept P rot = .
30 d from the first data set as the most fea-sible and accurate rotation period. Accordingly, for phase calcu-lations we use the following equation:HJD = , , . + . × E , (1)where the reference time was chosen arbitrarily (cf. Paper I).
4. Fundamental parameters
We redetermined the e ff ective temperature ( T e ff ), surface grav-ity (log g ), metallicity ([Fe / H]), and projected rotational velocity( v sin i ) via the spectrum-synthesis code ParSES (Allende Pri-eto 2004; Jovanovic et al. 2013) implemented in the standardSTELLA-SES data reduction process (Weber et al. 2008). Forthe synthetic spectra, we determined a microturbulence ξ mic of1.25 km s − by following the empirical relation as was used inthe Gaia-ESO survey (Jofré et al. 2014). The radial-tangentialmacroturbulence ξ mac of 3 km s − was taken from Fekel (1997),but see also Paper I. The resulting parameters with their inter-nal standard deviations are listed in Table 2. When compared tothe previous values in Paper I, the gravity log g and v sin i areonly slightly di ff erent; these values are still within the small er-ror boxes, but the e ff ective temperature of 4305 K is lower by ≈
200 K. However, the new, lower, value is in a better agreementwith the colour-index temperature calibration by Worthey & Lee(2011) when taking V − I C = m .
33 from the long-term photo-metric data. In Paper I V − I = m .
21 was taken from the Hip-parcos / Tycho catalogue, which would have been in accordancewith a temperature of ≈ ± − , and taking 65 ◦ inclination Article number, page 3 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr
Fig. 2.
Position of V1192 Ori (dot) in the H-R diagram. Shown are stel-lar evolutionary tracks for 1.6, 1.8, and 2.0 M (cid:12) from
PARSEC , assuming[Fe / H] = − M (cid:12) and an age of 1.6 Gyrs. Table 2.
Astrophysical properties of V1192 Ori
Parameter ValueSpectral type K2.5 IIIDistance
Gaia [pc] 327 + − V br [mag] 7 m . ± m . V − I ) C , br [mag] 1 m . ± m . M bol [mag] − m . + . − . Luminosity [ L (cid:12) ] 218 + − log g [cgs] 2 . ± . T e ff [K] 4305 ± v sin i [km s − ] 32 . ± . . ± . ◦ ] 65 ± R (cid:12) ] 19 . + . − . Mass [ M (cid:12) ] 1 . ± . . ± . − ] 1 . − ] 3.0Metallicity [Fe / H] − . ± . ± R = . + . − . R (cid:12) which, to-gether with T e ff = iMap (see Sect. 6.2) and obtained the mostacceptable inversions for a range of inclination angles between50 ◦ -70 ◦ . However, iMap works in a di ff erent way and is onlyof limited use to perform such a parameter search. Thus, we de-cided to keep the former inclination angle from Paper I assuminga slightly larger error bar of ± ◦ . From the radius and e ff ectivetemperature it follows that the luminosity L = + − L (cid:12) . Whenassuming M bol , (cid:12) = m .
74 this yields M bol = − m . + . − . .The improved parallax of 3.06 ± Gaia
DR1(Gaia Collaboration et al. 2016b,a; Lindegren et al. 2016) yieldsa distance of 327 + − pc, which is 25% larger compared to the Hipparcos distance of 238 + − (cf. Paper I). Based on our long- Fig. 3.
Observed Li i term APT photometry we are able to give a new estimationof 7 m . ± m .
10 for the brightest V magnitude observed so far(see V br in Table 2). Taking these improved values and assum-ing an interstellar extinction of A V = m .
191 (Schlegel et al.1998) together with a bolometric correction of BC = − m . M bol = − m . + . − . . This value andthat calculated from T e ff and R agree with each other withintheir errors. The value M bol derived from the Gaia parallax con-verts to a luminosity of 218 + − L (cid:12) , which we eventually adoptedto find the most plausible position of V1192 Ori in the H-Rdiagram in Fig. 2. We adopted the PARSEC stellar evolutiongrid by Bressan et al. (2012, 2013), interpolating for [Fe / H] of − = ± M (cid:12) with an age of 1.64 ± ± M (cid:12) from Paper I. Taking the massand radius would yield log g = . + . − . , i.e. a bit lower thanthe adopted value from ParSES. However, such a di ff erence canoriginate from, for example a somewhat underestimated V br (cf.Oláh et al. 2014), which would yield lower luminosity, thereforelower mass. Also, a 0.02 dex shift in metallicity yields a massdi ff erence of ≈
5. Surface Li abundance
In Fig. 3 we plot an average Li i -6708 Å spectrum from sum-ming up seven good-quality (S / N ratio of ≈ / N > A (Li) = .
20, i.e. somewhat lower than the value of1.4 ± T e ff yields an ≈ ffi cients. The fit resulted in A (Li) NLTE = .
27, in good agree-ment with the recent result by Rebull et al. (2015). We plot theLTE and the NLTE fits together in Fig. 3. Both the LTE andthe NLTE approach yields abundances lower than the anticipated
Article number, page 4 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori Table 3.
Temporal distribution of the Doppler images
Observing Doppler Mid-HJD Mid-date Number Data coverage Data coveragerun image 2 450 000 + yyyy-mm-dd of spectra [days] in P rot S11
Fig. 4.
Doppler image of V1192 Ori for the S11 data set. The corresponding mid-date is 2007-02-22. The spherical surface map is shown in fourrotational phases (identified on top) along with the temperature scale. limiting value of 1.5 for Li-rich giants. By applying the indepen-dent LTE-NLTE abundance correction of Klevas et al. (2016) toour LTE abundance yields A (Li) NLTE = .
46, i.e. also below thenominal 1.5. Thus, we conclude that V1192 Ori is actually nota bona fide Li-rich giant but a Li-normal star with high surfaceamounts of Li.
6. Doppler images for 2007–2016
Our spectroscopic data were taken during six observing runs be-tween 2007 and 2016, each providing fairly good sampling forthe relatively long rotational phase of 28.3 days. This data setallowed for altogether 11 Doppler reconstructions. Table 3 sum-marizes the temporal distribution of the Doppler reconstructionsover the six runs (see also Table A.1 in the Appendix). The sec-ond and the third runs were long and continuous enough forobtaining Doppler images for several consecutive stellar rota-tions, suitable for studying surface di ff erential rotation by track-ing short-term spot displacements (see Sect. 7). Our Doppler reconstruction code iMap performs multi-line in-version simultaneously for a large number of photospheric lineprofiles (Carroll et al. 2012). For the inversion we selected 40suitable absorption lines from the 5000–6750 Å wavelengthrange by their line depth, blends, continuum level, and their tem-perature sensitivity (Künstler et al. 2015). Each contributing line is modelled individually and locally and then disk-integrated; fi-nally, all disk-integrated line profiles are averaged to form themean line profile, which can be compared with each observedmean profile for each observed phase (for more details see Sect.3 in Carroll et al. 2012).The iMap code calculates the line profiles by solving the ra-diative transfer through an artificial neural network (Carroll et al.2008). Atomic parameters are taken from the VALD database(Kupka et al. 1999). Model atmospheres are taken from Castelli& Kurucz (2004) and are interpolated for each desired temper-ature, gravity, and metallicity. Owing to the high workload forcomputation and modelling, we used LTE radiative transfer in-stead of spherical model atmospheres. Nevertheless, limitationsfrom neglecting spherical model atmospheres and continuumscattering are compensated by using dense phase coverages (cf.Table 3) and also by using our multi-line approach. For the sur-face reconstruction iMap uses an iterative regularization basedon a Landweber algorithm (Carroll et al. 2012), and therefore noadditional constraints are imposed in the image domain. For theinversions we used the same stopping criteria as given by Car-roll et al. (2012). According to our tests (see Appendix A in theaforementioned reference) the iterative regularization (i.e. stepsize control & stopping rule) is proved to be enough to convergealways to the same image solution. The surface element resolu-tion is set to 5 ◦ × ◦ . Doppler reconstructions for V1192 Ori reveal a general charac-teristic; there are cool spots of di ff erent sizes and temperature Article number, page 5 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr
S21S22S23S24S25
Fig. 5.
Doppler images of V1192 Ori for the five data sets S21, S22, S23, S24, and S25. The corresponding mid-dates are 2007-09-09, 2007-10-06,2007-11-08, 2008-01-05, and 2008-02-09 , respectively. Otherwise as in Fig. 4. contrasts all around the equatorial regions within a belt extend-ing not higher than ≈ ◦ and a warm azimuthal belt at higherlatitudes or partly covering the pole. The individual cool spotschange in size considerably from one map to the next. The tem-perature of the coolest spots is ≈
700 K below the e ff ective tem- perature of the unspotted photosphere. On the other hand, nocool spots at all appear on or near the visible pole during thetime of observations, but the high latitude or even polar patchesof ≈
150 K warmer regions are seen repeatedly. The overall sur-face structure with cool spots at lower latitudes and warmer but
Article number, page 6 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori S31S32
Fig. 6.
Doppler images of V1192 Ori for the two data sets S31 and S32. The corresponding mid-dates are 2008-11-14 and 2008-12-19, respectively.Otherwise as in Fig. 4.
S41
Fig. 7.
Doppler image of V1192 Ori for the S41 data set. The corresponding mid-date is 2009-11-10. Otherwise as in Fig. 4.
S51
Fig. 8.
Doppler image of V1192 Ori for the S51 data set. The corresponding mid-date is 2011-02-23. Otherwise as in Fig. 4. weakly contrasted features at higher latitudes bears resemblancewith the first Doppler images from late 1996 in Paper I, eventhough those maps revealed lower temperature contrasts. Weevaluated the mean error for our temperature maps with a MonteCarlo analysis as described in Carroll et al. (2012) and found amaximum error of 110 K.
First run.
The very first season in early 2007 is covered bya single data set that allowed only one surface reconstruction,shown in Fig. 4. It reveals a chain of relatively large, partly ad-joined spots all around the star. The individual spots have dif-ferent contrasts but are always cooler than the e ff ective temper- ature by ≈ Second run.
The second season from late 2007 to early 2008is our best-sampled season and provides five maps with a sam-pling of one map per stellar rotation. Again, as in early 2007, sig-nificant changes of the spot arrangement are seen from one mapto the next. This is demonstrated in the time series of maps inFig. 5. Nevertheless, the corresponding dominant spots can eas-
Article number, page 7 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr
S61
Fig. 9.
Doppler image of V1192 Ori for the S61 data set. The corresponding mid-date is 2016-01-21. Otherwise as in Fig. 4. ily be tracked on the consecutive maps and, besides some degreeof sporadic displacements, the longitudinal tracks already indi-cate significant di ff erential surface rotation (cf. Sect. 7). This isparticularly intriguing because the range of latitudes with spotsas surface tracers is comparably narrow. There are also severalother noteworthy morphological details, for example a persistentlongitudinal gap between spots at around phase 0.4, or the onelatitudinally displaced spot at “southern” latitude. At this pointwe point out that the Doppler-imaging technique would likelyfail to resolve two close-together symmetric latitudinal belts ofindividual spots, for example as seen on our Sun. Simulationssuggested that it likely reconstructs only a single belt placed atthe sub-observers latitude (e.g. Rice & Strassmeier 2000). Third run.
For the third season in late 2008 (Fig. 6), we haveanother two consecutive maps. These maps again reveal spotrearrangements from one rotation to the next, which are partlymorphological in nature and partly longitudinal migrations ow-ing to di ff erential surface rotation. The morphological changeswere so rapid that there is almost no resemblance between thetwo maps; this is particularly the case, for example at phase 0.25in Fig. 6, even though they are from two consecutive rotations.Such rapid variations are also seen on the Sun for particularlyactive spot groups, while solar plages may not even live as longas one solar rotation. Because the rotation periods of V1192 Oriand the Sun are not so di ff erent, 28.3 d versus 25 d, we mayexpect that some of the features we are mapping had evolvedduring the time of observation. If so, only a time average spotwould be reconstructed. Fourth, fifth, and sixth runs.
Finally, for the rest of the data,namely from late 2009 (Fig. 7), early 2011 (Fig. 8), and early2016 (Fig. 9) only one Doppler image per season was possible.Yet, each one shows basically the same morphology, i.e. coolspots at low to mid-latitudes distributed quasi-evenly along allrotational phases and weakly contrasted warm features at veryhigh latitudes, but no cool spot at the pole itself.
7. Surface differential rotation from time-seriesDoppler images
The time-series Doppler images in the second and third observ-ing season allowed us to study the surface di ff erential rotation bymeans of a cross-correlation analysis of the consecutive maps.Our cross-correlation technique ACCORD (K˝ovári et al. 2015, andreferences therein) combines the available information from spotdisplacements in order to reconstruct the signature of the dif-ferential rotation. In the second season from late 2007 to early2008, we have five consecutive Doppler images (dubbed S21,S22, S23, S24, and S25), while in late 2008, we have two (S31and S32). Therefore, we are able to create altogether five image
Fig. 10.
Average cross-correlation map showing the evidence for sur-face di ff erential rotation. Darker regions represent better correlation.The average longitudinal cross-correlation functions in 5 ◦ bins are fittedby Gaussian curves. Gaussian peaks are indicated by dots and the cor-responding Gaussian widths by horizontal lines. The continuous line isthe best fit, suggesting antisolar di ff erential rotation with P eq = .
35 dequatorial period and α = − .
11 surface shear. pairs (S21-S22, S22-S23, S23-S24, S24-S25, and S31-S32) tobe cross-correlated. These correlation maps are combined andthe average correlation pattern is fitted with a quadratic rotationlaw. The result is shown in Fig. 10 and indicates antisolar di ff er-ential rotation, i.e. on V1192 Ori the rotation rate increases fromthe equator towards the pole. Its rotation law is expressed in theform Ω ( β ) = Ω eq (1 − α sin β ), where Ω ( β ) is the angular veloc-ity at β latitude, Ω eq is the angular velocity at the equator, while α is the dimensionless surface shear coe ffi cient obtained from( Ω eq − Ω pole ) / Ω eq , i.e. the angular velocity di ff erence betweenthe equator and the pole divided by the equatorial velocity. Thebest fit yields Ω eq = . ± . ◦ / d and α = − . ± . ≈
260 days, that is the timethe polar regions need to lap the equator by one full rotation.
8. Summary and discussions
An extended Doppler imaging study with STELLA during theyears 2007 to 2016 yielded 11 new surface image reconstruc-tions, typically one image per stellar rotation. The 11 newDoppler images closely resemble the first Doppler image ofV1192 Ori in Paper I from 1996-97 taken with a di ff erenttelescope-spectrograph combination and with a di ff erent inver-sion code. Its surface spot distribution is well characterized inthe sense that cool spots of di ff erent sizes and temperatures are Article number, page 8 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori Table 4.
Surface shear parameters obtained by cross-correlation of subsequent Doppler images
Star Type P rot [d] α surface shear ReferenceAB Dor K0V, single 0.51 + ± + ± + ± − ± − . ± + ± − ± ζ And K1III, binary 17.76 + ± − ± σ Gem K1III, binary 19.60 − ± + ± + ± − ± ≈ ◦ and centred at the sub-observers latitude. No coolspots appear on or near the visible polar region. On the otherhand, the individual spots change dynamically, not only fromone observing season to the next but from one rotation to thenext and possibly even within a single stellar rotation. A warmfeature appears consistently at high latitudes as a (partial) az-imuthal ring around the pole but we are not certain of its reality.Even though there are now maps spanning 20 years, one cannotidentify a clear cyclic behaviour or trend. Long-term variabilityis certainly present in the photometric light curve on a timescaleof 5–10 years (Fig. 1). However, the 10-yr gap in the photometricdata from March 1997 to March 2007 prevents us from suggest-ing any cycle length. We nevertheless refine the rotation periodof V1192 Ori from these data to 28.30 days and derive a morereliable set of fundamental stellar parameters by comparing toupdated evolutionary tracks. Accordingly, the spectral type ofV1192 Ori is found to be K2.5III, i.e. 0.5 subclasses cooler thanclaimed earlier.For the time-series Doppler images from the years 2007–2008, we applied our robust cross-correlation technique andfound strong antisolar di ff erential rotation with an α = − . ffi cient. This result is in very good agreementwith the earlier result of − .
12 from the independent data in Pa-per I. This is the case even though the α value in Paper I wasderived only from a single cross-correlation of two consecutiveDoppler maps, and therefore was significantly less robust andhad larger error bars. With the present result, we are now con-fident that V1192 Ori indeed shows strong antisolar di ff erentialrotation. Together with DI Psc (Kriskovics et al. 2014) this isthe strongest antisolar shear coe ffi cient measured to date. Suchstrong shear supports the relation of | α | ∝ P rot , i.e. the lowerthe rotation the stronger the shear (K˝ovári & Oláh 2014). Also,a Rossby number of 0.22 derived for V1192 Ori (Aurière et al.2015) indicates that an α Ω -type dynamo is operating underneath,i.e. di ff erential rotation is expected to play an important role. Ta-ble 4 compares V1192 Ori to other measurements of di ff erentialsurface rotation. The list is not complete and, for the sake of ho-mogeneity, only results from Doppler-imaging studies applyingthe cross-correlation technique are listed.The unusually fast rotation of a single, evolved star such asV1192 Ori can be explained in various ways, including angu-lar momentum transport from the deep interior (Simon & Drake1989). The mass of 1.85 M (cid:12) found for V1192 Ori implies a pre-cursor A5 spectral type on the main sequence (Ribas et al. 1997) or even earlier in the case of a significant mass loss. Such a stardoes not have a deep outer convective zone to maintain a pow-erful magnetic dynamo that would result in e ff ective magneticbraking on the main sequence (cf. Privitera et al. 2016a). Even-tually this means more angular momentum conservation for thepost-main sequence evolution, supporting the scenario of mix-ing up angular momentum. The position in the H-R diagram pastthe RGB luminosity bump (see Fig.2) indicates that V1192 Orihas completed Li production at the red-giant bump. Accordingto Charbonnel & Balachandran (2000) the Li production is fol-lowed by an extra mixing phase, interconnecting the CN-burningzone with the convective envelope. Although the Li enrichmentis relatively short lived, the extra mixing might explain the sur-face Li enrichment together with the peculiar rotation pattern.This is because freshly synthesized Li comes up to the surfacealong with high angular momentum material, which can even-tually be conveyed towards the poles, resulting in the observedantisolar surface di ff erential rotation (cf. Kitchatinov & Rüdiger2004).This scenario is also compatible with the Cameron-Fowlermechanism (Cameron & Fowler 1971) of Li production to-gether with the so-called cool-bottom processes (Sackmann &Boothroyd 1999), which are thought to be responsible for bring-ing down material from the convective zone and exposing thatmaterial to higher temperatures in which partial nuclear fusion(H burning) occurs. Then, the Li-rich material is transportedback to the convective zone by some circulation or di ff usion,wherefrom convective mixing spreads it out towards the surface(see also Busso et al. 2007, and their references). The competingscenario of planet engulfment (cf. Mott et al. 2017, their Sect. 6and the references therein) explains the existence of the Li iso-tope in stellar atmospheres and may explain the rapid rotation aswell, however, it would not easily account for antisolar di ff eren-tial rotation. Acknowledgements.
Authors thank the anonymous referee for his / her valuablecomments and suggestions. We thank Dr. Johanna Jurcsik for her helpful noteson deriving the correct rotation period by Fourier transformation. This paperis based on data obtained with the STELLA robotic telescopes in Tenerife, anAIP facility jointly operated by AIP and IAC (https: // stella.aip.de / ) and by theAmadeus APT jointly operated by AIP and Fairborn Observatory in Arizona.For their continuous support, we are grateful to the ministry for research andculture of the State of Brandenburg (MWFK) and the German federal min-istry for education and research (BMBF). Authors from Konkoly Observatoryare grateful to the Hungarian National Research, Development and InnovationO ffi ce grants OTKA K-109276 and OTKA K-113117, and acknowledge sup-port from the Austrian-Hungarian Action Foundation (OMAA). KV is sup-ported by the Bolyai János Research Scholarship of the Hungarian Academy Article number, page 9 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr of Sciences. The authors acknowledge the support of the German
DeutscheForschungsgemeinschaft, DFG through projects KO2320 / /
1. Thiswork has made use of data from the European Space Agency (ESA) mission
Gaia ( ), processed by the Gaia
Data Process-ing and Analysis Consortium (DPAC, ). Funding for the DPAC has been provided by na-tional institutions, in particular the institutions participating in the
Gaia
Mul-tilateral Agreement.
References
Allende Prieto, C. 2004, Astronomische Nachrichten, 325, 604Aurière, M., Konstantinova-Antova, R., Charbonnel, C., et al. 2015, A&A, 574,A90Aurnou, J., Heimpel, M., & Wicht, J. 2007, Icarus, 190, 110Bidelman, W. P. & MacConnell, D. J. 1973, AJ, 78, 687Bressan, A., Marigo, P., Girardi, L., Nanni, A., & Rubele, S. 2013, in EuropeanPhysical Journal Web of Conferences, Vol. 43, European Physical JournalWeb of Conferences, 03001Bressan, A., Marigo, P., Girardi, L., et al. 2012, MNRAS, 427, 127Busso, M., Wasserburg, G. J., Nollett, K. M., & Calandra, A. 2007, ApJ, 671,802Cameron, A. G. W. & Fowler, W. A. 1971, ApJ, 164, 111Carroll, T. A., Kopf, M., & Strassmeier, K. G. 2008, A&A, 488, 781Carroll, T. A., Strassmeier, K. G., Rice, J. B., & Künstler, A. 2012, A&A, 548,A95Castelli, F. & Kurucz, R. L. 2004, ArXiv Astrophysics e-printsCastilho, B. V., Gregorio-Hetem, J., Spite, F., Barbuy, B., & Spite, M. 2000,A&A, 364, 674Charbonnel, C. & Balachandran, S. C. 2000, A&A, 359, 563Charbonnel, C. & Lagarde, N. 2010, A&A, 522, A10Csubry, Z. & Kolláth, Z. 2004, in ESA Special Publication, Vol. 559, SOHO 14Helio- and Asteroseismology: Towards a Golden Future, ed. D. Danesy, 396Cutri, R. M., Skrutskie, M. F., van Dyk, S., et al. 2003, VizieR Online DataCatalog, 2246de La Reza, R., Drake, N. A., & da Silva, L. 1996, ApJ, 456, L115de la Reza, R., Drake, N. A., da Silva, L., Torres, C. A. O., & Martin, E. L. 1997,ApJ, 482, L77Donati, J.-F. & Collier Cameron, A. 1997, MNRAS, 291, 1Dyck, H. M., Benson, J. A., van Belle, G. T., & Ridgway, S. T. 1996, AJ, 111,1705Fekel, F. C. 1988, in ESA Special Publication, Vol. 281, ESA Special PublicationFekel, F. C. 1997, PASP, 109, 514Fekel, F. C. & Balachandran, S. 1993, ApJ, 403, 708Fekel, F. C., Mo ff ett, T. J., & Henry, G. W. 1986, ApJS, 60, 551Flower, P. J. 1996, ApJ, 469, 355Gaia Collaboration, Brown, A. G. A., Vallenari, A., et al. 2016a, A&A, 595, A2Gaia Collaboration, Prusti, T., de Bruijne, J. H. J., et al. 2016b, A&A, 595, A1Gastine, T., Yadav, R. K., Morin, J., Reiners, A., & Wicht, J. 2014, MNRAS,438, L76Gezari, D. Y., Pitts, P. S., & Schmitz, M. 1999, VizieR Online Data Catalog,2225Gioia, I. M., Maccacaro, T., Schild, R. E., et al. 1990, ApJS, 72, 567Granzer, T., Reegen, P., & Strassmeier, K. G. 2001, Astronomische Nachrichten,322, 325Gustafsson, B., Edvardsson, B., Eriksson, K., et al. 2008, A&A, 486, 951Harutyunyan, G., Strassmeier, K. G., Künstler, A., Carroll, T. A., & Weber, M.2016, A&A, 592, A117Jofré, P., Heiter, U., Soubiran, C., et al. 2014, A&A, 564, A133Jovanovic, M., Weber, M., & Allende Prieto, C. 2013, Publications del’Observatoire Astronomique de Beograd, 92, 169Käpylä, P. J., Käpylä, M. J., & Brandenburg, A. 2014, A&A, 570, A43K˝ovári, Zs., Korhonen, H., Kriskovics, L., et al. 2012, A&A, 539, A50K˝ovári, Zs., Korhonen, H., Strassmeier, K. G., et al. 2013, A&A, 551, A2K˝ovári, Zs., Kriskovics, L., Künstler, A., et al. 2015, A&A, 573, A98K˝ovári, Zs., Kriskovics, L., Oláh, K., et al. 2014, in IAU Symposium, Vol. 302,Magnetic Fields throughout Stellar Evolution, ed. P. Petit, M. Jardine, & H. C.Spruit, 379–380K˝ovári, Zs., Künstler, A., Strassmeier, K. G., et al. 2016, A&A, 596, A53K˝ovári, Zs. & Oláh, K. 2014, Space Sci. Rev., 186, 457K˝ovári, Zs., Strassmeier, K. G., Granzer, T., et al. 2004, A&A, 417, 1047K˝ovári, Zs., Washuettl, A., Foing, B. H., et al. 2009, in American Institute ofPhysics Conference Series, Vol. 1094, 15th Cambridge Workshop on CoolStars, Stellar Systems, and the Sun, ed. E. Stempels, 676–679Kirby, E. N., Guhathakurta, P., Zhang, A. J., et al. 2016, ApJ, 819, 135Kitchatinov, L. L. & Rüdiger, G. 2004, Astronomische Nachrichten, 325, 496Klevas, J., Kuˇcinskas, A., Ste ff en, M., Ca ff au, E., & Ludwig, H.-G. 2016, A&A,586, A156 Kriskovics, L., K˝ovári, Zs., Vida, K., Granzer, T., & Oláh, K. 2014, A&A, 571,A74Künstler, A., Carroll, T. A., & Strassmeier, K. G. 2015, A&A, 578, A101Kupka, F., Piskunov, N., Ryabchikova, T. A., Stempels, H. C., & Weiss, W. W.1999, A&AS, 138, 119Lindegren, L., Lammers, U., Bastian, U., et al. 2016, A&A, 595, A4Mott, A., Ste ff en, M., Ca ff au, E., Spada, F., & Strassmeier, K. G. 2017, ArXive-printsOláh, K., Moór, A., K˝ovári, Z., et al. 2014, A&A, 572, A94Özdarcan, O., Carroll, T. A., Künstler, A., et al. 2016, A&A, 593, A123Piskunov, N. & Valenti, J. A. 2017, A&A, 597, A16Privitera, G., Meynet, G., Eggenberger, P., et al. 2016a, A&A, 591, A45Privitera, G., Meynet, G., Eggenberger, P., et al. 2016b, A&A, 593, A128Rebull, L. M., Carlberg, J. K., Gibbs, J. C., et al. 2015, AJ, 150, 123Reinhold, T. & Arlt, R. 2015, A&A, 576, A15Ribas, I., Jordi, C., Torra, J., & Gimenez, A. 1997, A&A, 327, 207Rice, J. B. & Strassmeier, K. G. 2000, A&AS, 147, 151Sackmann, I.-J. & Boothroyd, A. I. 1992, ApJ, 392, L71Sackmann, I.-J. & Boothroyd, A. I. 1999, ApJ, 510, 217Schlegel, D. J., Finkbeiner, D. P., & Davis, M. 1998, ApJ, 500, 525Simon, T. & Drake, S. A. 1989, ApJ, 346, 303Slee, O. B., Nelson, G. J., Stewart, R. T., et al. 1987, MNRAS, 229, 659Strassmeier, K. G., Bartus, J., Cutispoto, G., & Rodono, M. 1997a, A&AS, 125Strassmeier, K. G., Boyd, L. J., Epand, D. H., & Granzer, T. 1997b, PASP, 109,697Strassmeier, K. G., Carroll, T. A., Weber, M., & Granzer, T. 2015, A&A, 574,A31Strassmeier, K. G., Fekel, F. C., Bopp, B. W., Dempsey, R. C., & Henry, G. W.1990, ApJS, 72, 191Strassmeier, K. G., Granzer, T., Weber, M., et al. 2010, Advances in Astronomy,2010, 19Strassmeier, K. G., Kratzwald, L., & Weber, M. 2003, A&A, 408, 1103Strassmeier, K. G., Serkowitsch, E., & Granzer, T. 1999, A&AS, 140, 29van Belle, G. T., Lane, B. F., Thompson, R. R., et al. 1999, AJ, 117, 521Vida, K., K˝ovári, Zs., Švanda, M., et al. 2007, Astronomische Nachrichten, 328,1078Voges, W., Aschenbach, B., Boller, T., et al. 1999, A&A, 349, 389Vogt, S. S. & Hatzes, A. P. 1991, in Lecture Notes in Physics, Berlin SpringerVerlag, Vol. 380, IAU Colloq. 130: The Sun and Cool Stars. Activity, Mag-netism, Dynamos, ed. I. Tuominen, D. Moss, & G. Rüdiger, 297Wasserburg, G. J., Boothroyd, A. I., & Sackmann, I.-J. 1995, ApJ, 447, L37Weber, M., Granzer, T., & Strassmeier, K. G. 2012, in Society of Photo-OpticalInstrumentation Engineers (SPIE) Conference Series, Vol. 8451, Society ofPhoto-Optical Instrumentation Engineers (SPIE) Conference Series, 0Weber, M., Granzer, T., Strassmeier, K. G., & Woche, M. 2008, in Societyof Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol.7019, Society of Photo-Optical Instrumentation Engineers (SPIE) ConferenceSeries, 0Weber, M. & Strassmeier, K. G. 2011, A&A, 531, A89Worthey, G. & Lee, H.-c. 2011, ApJS, 193, 1 Appendix A: Observing log of the spectroscopicdata and line profile fits for each individualsurface reconstruction
Article number, page 10 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori Table A.1.
Observing log of STELLA-SES spectra of V1192 Ori from 2007–2016 and grouping into subsets for Doppler reconstructions
HJD a Phase b Date S / N Subset HJD a Phase b Date S / N Subset4140.464 0.260 08.02.2007 253 S11 4382.641 0.818 09.10.2007 147 S224141.454 0.295 09.02.2007 296 S11 4383.644 0.853 10.10.2007 203 S224142.454 0.331 10.02.2007 274 S11 4384.638 0.888 11.10.2007 132 S224143.455 0.366 11.02.2007 298 S11 4387.646 0.995 14.10.2007 186 S224144.447 0.401 12.02.2007 185 S11 4388.658 0.030 15.10.2007 182 S224146.456 0.472 14.02.2007 309 S11 4389.635 0.065 16.10.2007 183 S224147.414 0.506 15.02.2007 264 S11 4390.614 0.099 17.10.2007 74 S224148.397 0.541 16.02.2007 267 S11 4392.647 0.171 19.10.2007 182 S224150.417 0.612 18.02.2007 283 S11 4393.646 0.207 20.10.2007 140 S224152.458 0.684 20.02.2007 279 S11 4395.630 0.277 22.10.2007 123 S234153.458 0.719 21.02.2007 278 S11 4396.614 0.311 23.10.2007 137 S234154.476 0.755 22.02.2007 252 S11 4398.579 0.381 25.10.2007 126 S234155.480 0.791 23.02.2007 275 S11 4399.574 0.416 26.10.2007 125 S234156.459 0.825 24.02.2007 186 S11 4400.698 0.456 27.10.2007 122 S234157.460 0.861 25.02.2007 158 S11 4402.601 0.523 29.10.2007 164 S234158.460 0.896 26.02.2007 253 S11 4403.584 0.558 30.10.2007 110 S234159.459 0.931 27.02.2007 240 S11 4404.677 0.596 31.10.2007 162 S234160.461 0.967 28.02.2007 237 S11 4405.591 0.629 01.11.2007 177 S234162.384 0.035 02.03.2007 323 S11 4406.607 0.665 02.11.2007 151 S234163.361 0.069 03.03.2007 262 S11 4412.639 0.878 08.11.2007 57 S234164.389 0.106 04.03.2007 304 S11 4412.711 0.880 08.11.2007 79 S234165.375 0.140 05.03.2007 263 S11 4413.659 0.914 09.11.2007 156 S234166.378 0.176 06.03.2007 294 S11 4414.550 0.945 10.11.2007 92 S234167.378 0.211 07.03.2007 303 S11 4414.704 0.951 10.11.2007 121 S234338.707 0.265 26.08.2007 144 S21 4416.545 0.016 12.11.2007 52 S234339.684 0.300 27.08.2007 136 S21 4416.622 0.018 12.11.2007 174 S234340.684 0.335 28.08.2007 101 S21 4417.562 0.052 13.11.2007 126 S234343.685 0.441 31.08.2007 145 S21 4417.687 0.056 13.11.2007 121 S234345.673 0.511 02.09.2007 131 S21 4418.583 0.088 14.11.2007 117 S234346.672 0.547 03.09.2007 137 S21 4419.578 0.123 15.11.2007 141 S234347.674 0.582 04.09.2007 122 S21 4420.574 0.158 16.11.2007 146 S234349.697 0.654 06.09.2007 151 S21 4421.578 0.194 17.11.2007 144 S234350.699 0.689 07.09.2007 151 S21 4422.683 0.233 18.11.2007 148 S234351.692 0.724 08.09.2007 141 S21 4423.575 0.264 19.11.2007 177 S234352.693 0.759 09.09.2007 162 S21 4437.679 0.763 03.12.2007 220 S234353.693 0.795 10.09.2007 129 S21 4438.580 0.794 04.12.2007 327 S234354.688 0.830 11.09.2007 145 S21 4450.470 0.214 15.12.2007 395 S244355.692 0.865 12.09.2007 155 S21 4459.403 0.530 24.12.2007 271 S244357.683 0.936 14.09.2007 156 S21 4460.401 0.565 25.12.2007 330 S244358.695 0.972 15.09.2007 107 S21 4461.402 0.601 26.12.2007 352 S244359.672 0.006 16.09.2007 153 S21 4462.394 0.636 27.12.2007 342 S244360.673 0.041 17.09.2007 137 S21 4463.399 0.671 28.12.2007 327 S244361.669 0.077 18.09.2007 133 S21 4464.408 0.707 29.12.2007 356 S244362.669 0.112 19.09.2007 153 S21 4465.388 0.742 30.12.2007 351 S244363.672 0.147 20.09.2007 144 S21 4466.386 0.777 31.12.2007 344 S244364.667 0.183 21.09.2007 131 S21 4467.406 0.813 01.01.2008 306 S244365.675 0.218 22.09.2007 122 S21 4468.379 0.847 02.01.2008 328 S244366.689 0.254 23.09.2007 137 S22 4469.589 0.890 04.01.2008 263 S244367.650 0.288 24.09.2007 55 S22 4471.443 0.956 05.01.2008 319 S244369.656 0.359 26.09.2007 108 S22 4475.452 0.097 09.01.2008 357 S244370.684 0.395 27.09.2007 149 S22 4479.446 0.238 13.01.2008 315 S244371.702 0.431 28.09.2007 166 S22 4481.448 0.309 15.01.2008 334 S244372.664 0.465 29.09.2007 164 S22 4482.456 0.345 16.01.2008 325 S244373.664 0.501 30.09.2007 139 S22 4483.452 0.380 17.01.2008 344 S244377.662 0.642 04.10.2007 138 S22 4484.418 0.414 18.01.2008 203 S244378.653 0.677 05.10.2007 126 S22 4485.438 0.450 19.01.2008 182 S244379.649 0.712 06.10.2007 158 S22 4486.470 0.487 20.01.2008 274 S244380.641 0.747 07.10.2007 161 S22 4488.410 0.555 22.01.2008 89 S25 a + b Phases computed using Eq. 1. Article number, page 11 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr
Table A.1. continued.
HJD a Phase b Date S / N Subset HJD a Phase b Date S / N Subset4488.481 0.558 22.01.2008 216 S25 5122.662 0.967 18.10.2009 299 S414490.497 0.629 24.01.2008 308 S25 5124.655 0.037 20.10.2009 149 S414491.452 0.663 25.01.2008 270 S25 5134.656 0.391 30.10.2009 292 S414492.389 0.696 26.01.2008 67 S25 5135.626 0.425 31.10.2009 336 S414494.422 0.768 28.01.2008 280 S25 5139.602 0.565 04.11.2009 318 S414495.407 0.802 29.01.2008 242 S25 5140.564 0.599 05.11.2009 126 S414496.454 0.839 30.01.2008 249 S25 5142.595 0.671 07.11.2009 270 S414499.444 0.945 02.02.2008 257 S25 5143.599 0.707 08.11.2009 250 S414501.456 0.016 04.02.2008 312 S25 5144.595 0.742 09.11.2009 273 S414502.457 0.052 05.02.2008 298 S25 5146.583 0.812 11.11.2009 323 S414508.460 0.264 11.02.2008 250 S25 5147.555 0.846 12.11.2009 146 S414512.461 0.405 15.02.2008 235 S25 5149.594 0.919 14.11.2009 225 S414514.462 0.476 17.02.2008 263 S25 5154.592 0.095 19.11.2009 251 S414515.461 0.511 18.02.2008 239 S25 5155.602 0.131 20.11.2009 279 S414516.461 0.546 19.02.2008 220 S25 5156.583 0.165 21.11.2009 159 S414532.378 0.109 06.03.2008 326 S25 5157.589 0.201 22.11.2009 268 S414533.379 0.144 07.03.2008 253 S25 5159.653 0.274 24.11.2009 315 S414534.379 0.179 08.03.2008 305 S25 5160.591 0.307 25.11.2009 307 S414774.642 0.669 04.11.2008 220 S31 5161.586 0.342 26.11.2009 256 S414775.595 0.703 05.11.2008 97 S31 5601.457 0.885 08.02.2011 72 S514775.639 0.705 05.11.2008 128 S31 5603.407 0.954 10.02.2011 96 S514775.726 0.708 05.11.2008 197 S31 5607.468 0.098 14.02.2011 107 S514776.644 0.740 06.11.2008 92 S31 5612.403 0.272 19.02.2011 114 S514776.733 0.743 06.11.2008 117 S31 5615.377 0.377 22.02.2011 115 S514777.595 0.774 07.11.2008 220 S31 5616.374 0.412 23.02.2011 113 S514778.595 0.809 08.11.2008 209 S31 5617.370 0.448 24.02.2011 139 S514779.590 0.844 09.11.2008 283 S31 5618.370 0.483 25.02.2011 110 S514780.586 0.879 10.11.2008 264 S31 5619.377 0.519 26.02.2011 91 S514781.670 0.918 11.11.2008 130 S31 5620.379 0.554 27.02.2011 59 S514783.586 0.985 13.11.2008 208 S31 5623.371 0.660 02.03.2011 122 S514784.581 0.021 14.11.2008 260 S31 5639.376 0.225 18.03.2011 94 S514785.581 0.056 15.11.2008 256 S31 7396.439 0.312 08.01.2016 182 S614789.583 0.197 19.11.2008 240 S31 7397.478 0.349 09.01.2016 387 S614793.594 0.339 23.11.2008 222 S31 7398.456 0.384 10.01.2016 364 S614794.588 0.374 24.11.2008 229 S31 7399.476 0.420 11.01.2016 359 S614795.584 0.409 25.11.2008 232 S31 7400.476 0.455 12.01.2016 372 S614798.671 0.518 28.11.2008 228 S31 7401.474 0.490 13.01.2016 196 S614799.533 0.549 28.11.2008 225 S31 7402.526 0.527 14.01.2016 324 S614800.593 0.586 30.11.2008 252 S31 7403.585 0.565 16.01.2016 200 S614801.593 0.622 01.12.2008 214 S31 7404.503 0.597 16.01.2016 350 S614805.597 0.763 05.12.2008 218 S32 7406.523 0.669 18.01.2016 365 S614808.589 0.869 08.12.2008 232 S32 7407.477 0.702 19.01.2016 406 S614809.663 0.907 09.12.2008 245 S32 7408.503 0.739 20.01.2016 395 S614810.591 0.940 10.12.2008 173 S32 7409.461 0.772 21.01.2016 361 S614811.596 0.975 11.12.2008 222 S32 7410.461 0.808 22.01.2016 326 S614812.595 0.010 12.12.2008 183 S32 7411.463 0.843 23.01.2016 370 S614814.603 0.081 14.12.2008 164 S32 7412.485 0.879 24.01.2016 377 S614817.606 0.187 17.12.2008 220 S32 7413.499 0.915 25.01.2016 364 S614818.494 0.219 17.12.2008 246 S32 7414.464 0.949 26.01.2016 405 S614819.470 0.253 18.12.2008 141 S32 7415.463 0.985 27.01.2016 390 S614822.479 0.360 21.12.2008 234 S32 7416.489 0.021 28.01.2016 187 S614827.430 0.535 26.12.2008 65 S32 7418.476 0.091 30.01.2016 361 S614828.460 0.571 27.12.2008 229 S32 7419.485 0.127 31.01.2016 242 S614829.451 0.606 28.12.2008 147 S32 7420.453 0.161 01.02.2016 69 S614834.442 0.782 02.01.2009 293 S32 7421.441 0.196 02.02.2016 195 S614835.440 0.818 03.01.2009 236 S32 7422.464 0.232 03.02.2016 277 S614836.441 0.853 04.01.2009 232 S32 a + b Phases computed using Eq. 1.Article number, page 12 of 14˝ovári et al.: Antisolar di ff erential rotation and surface lithium enrichment on V1192 Ori S11 S21 S22
Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5
I/I C S23 S24 S25
Stokes I −50 0 50Velocity [km/s]1234
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.0
I/I C Fig. A.1.
Line profile fits for the Doppler reconstructions shown in Figs. 4–5. The phases of the individual observations are listed on the right sideof the panels. Article number, page 13 of 14 & A proofs: manuscript no. kovarietal_langed__31100_corr
S31 S32
Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.0
I/I C S41 S51 S61
Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.0
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.0
I/I C Stokes I −50 0 50Velocity [km/s]1.01.52.02.53.03.5