J/ApJ/893/11ivo://CDS.VizieR/J/ApJ/893/11doi:10.26093/cds/vizier.18930011CDSSoraisam M.D.Bildsten L.Drout M.R.Prince T.A.Kupfer T.Masci F.,Laher R.R.Kulkarni S.R.2022-09-07T06:36:00Z2021-09-22T07:40:57ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesgiant-starsstellar-spectral-typesinfrared-photometryvisible-astronomyphotometrysurveysUsing data from the (intermediate) Palomar Transient Factory (iPTF), we characterize the time variability of ~500 massive stars in M31. Our sample is those stars that are spectrally typed by Massey and collaborators, including Luminous Blue Variables, Wolf-Rayets, and warm and cool supergiants. We use the high-cadence, long-baseline (~5yr) data from the iPTF survey, coupled with data-processing tools that model complex features in the light curves. We find widespread photometric (R-band) variability in the upper Hertzsprung Russell diagram (or CMD) with an increasing prevalence of variability with later spectral types. Red stars (V-I>1.5) exhibit larger amplitude fluctuations than their bluer counterparts. We extract a characteristic variability timescale, t_ch_, via wavelet transformations that are sensitive to both continuous and localized fluctuations. Cool supergiants are characterized by longer timescales (>100 days) than the hotter stars. The latter have typical timescales of tens of days but cover a wider range, from our resolution limit of a few days to longer than 100 days. Using a 60 night block of data straddling two nights with a cadence of around 2 minutes, we extracted t_ch_ in the range 0.1-10 days with amplitudes of a few percent for 13 stars. Though there is broad agreement between the observed variability characteristics in the different parts of the upper CMD with theoretical predictions, detailed comparison requires models with a more comprehensive treatment of the various physical processes operating in these stars, such as pulsation, subsurface convection, and the effect of binary companions.2020ApJ...893...11Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/893/11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)I/345 : Gaia DR2 (Gaia Collaboration, 2018)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)J/A+A/366/508 : S Dor variables (van Genderen+, 2001)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/AJ/134/2474 : Ha emission-line stars in 7 dwarfs galaxies (Massey+, 2007)J/AJ/140/14 : Variability of luminous stars in LMC (Szczygiel+, 2010)J/A+A/509/A70 : Study of an eclipsing binary in M31 (Vilardell+, 2010)J/ApJ/727/53 : Red supergiant stars in the LMC. I. (Yang+, 2011)J/ApJ/759/11 : Wolf-Rayet content of M31 (Neugent+, 2012)J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)J/ApJ/754/35 : Red supergiant stars in the SMC. II. (Yang+, 2012)J/other/ApSS/345.133 : Photometric variability of WR 103 (van Genderen+, 2013)J/A+A/562/A125 : OGLE-III SMC massive stars VI light curves (Kourniotis+, 2014)J/ApJ/789/10 : M33 WR and Of-type Stars (Neugent+, 2014)J/A+A/570/A3 : Optical spectrum of HD50975 (Sperauskas+, 2014)J/A+A/580/A93 : VLTS. B stars multiplicity (Dunstall+, 2015)J/ApJ/826/224 : RSG and foreground candidates in M31 (Massey+, 2016)J/AJ/152/62 : Revised LGGS UBVRI phot. of M31 and M33 stars (Massey+, 2016)J/ApJ/844/40 : Variable stars in M31 & M33. V. HR diagram (Humphreys+, 2017)J/ApJ/859/140 : Multi-band magnitudes for W UMa EB* candidates (Chen+, 2018)J/ApJ/864/111 : HST/ACS one-year observations of M51 stars (Conroy+, 2018)J/ApJ/859/73 : Variability of RSGs in M31 from iPTF (Soraisam+, 2018)J/A+A/618/A185 : VI magnitudes of NGC 4535 stars (Spetsieri+, 2018)J/A+A/623/A110 : Gaia DR2. Variable stars in CMD (Gaia Collaboration+, 2019)J/A+A/624/A129 : 30 Dor red supergiant stars radial velocities (Patrick+, 2019)J/ApJ/872/L9 : TESS obs. of massive O and B stars (Pedersen+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/893/11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/893/11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/893/11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/893/11https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/893/11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/893/11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/893/11/table2 (Variability characteristics of massive stars in M31)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/893/11/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/893/11/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/893/11/table2?GETtext/xml+votable180.050000true10.942416741.25416670.0055555555555555566/2622-2623 2666 2708-2709 2752https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/893/11?format=asciiOpticalInfrareddefaultJ/ApJ/893/11/table2Variability characteristics of massive stars in M31recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLGGSStar identifier (JHHMMSS.ss+DDMMSS.s) (1)meta.id;meta.maincharm_LGGSLGGS component for J004147.24+410647.5 (1)meta.code.multipcharSpTSpectral classification (1)src.spTypecharRmag[14.8/20] PTF R-band mean magnitude of the lightcurvemagphot.mag;em.opt.RfloatRMS[0.01/0.7] RMS value of the lightcurvemagstat.stdev;phot.magfloatTimescaleCharacteristic timescale t_ch_ (2)dtime.scalecharPapIDisplay data from Paper I (Soraisam+, 2018, J/ApJ/859/73)meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from LGGS names (right ascension part)degpos.eq.ra;meta.main_DEPositions from LGGS names (declination part)degpos.eq.dec;meta.main