J/AJ/158/175ivo://CDS.VizieR/J/AJ/158/175doi:10.26093/cds/vizier.51580175CDSJoshi Y.C.Sharma K.Gangopadhyay A.Gokhale R.Misra K.2019-12-16T08:36:04Z2019-12-16T09:28:47ZCDS support team

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

cds-question@unistra.frgalaxiessupergiant-starsvariable-starsinfrared-photometryvisible-astronomyphotometryspectroscopyWe present a photometric and spectroscopic analysis of the Hubble-Sandage variable star AF And in M31. The data have been taken under the Nainital Microlensing Survey during 1998-2002, and follow-up observations were carried out until 2011. During this period, photometric observations in Cousins R and I bands were obtained for 169 nights spanning about 5000 days. AF And showed a prominent outburst around 1999 mid-January, followed by a gradual decrease in brightness of about 1.5 mag in the next 3 yr with a declining rate of ~0.0015 mag/day, leading to a quiescent phase at the end of 2001. After lying low for about 9 yr, AF And again went through a secondary outburst phase in late 2010 with an amplitude of 0.44 mag, where it lasted for one year before fading back to its quiescent phase. Spectroscopic observations of AF And show prominent Balmer and He I emission lines along with the comparatively weaker Fe II and [Fe II] emissions. Asymmetric emission line profiles in its spectrum imply a mass-loss rate of about 2.2x10^-4^ M_{sun}_/yr through the stellar winds in the photosphere. Using spectral energy distribution fitting, we find a photospheric temperature of 33000+/-3000 K during the visual minimum. Using a weak P Cygni profile of the He I emission line, the wind terminal velocity for AF And is found to be around 280-300 km/s.2019AJ....158..175Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/158/175CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/402/113 : (RI)c photometry of variables in M31 (Joshi+, 2003)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/ApJ/790/48 : Variable stars in M31 & M33. II. LBVs (Humphreys+, 2014)J/AJ/152/62 : Revised LGGS UBVRI of M31 and M33 stars (Massey+, 2016)J/ApJ/825/50 : Variable stars in M31 & M33. III. (Gordon+, 2016)J/AJ/154/81 : BVRI photometry of luminous stars in M31 and M33J/ApJ/836/64 : Luminous variable stars in M31 & M33. IV. (Humphreys+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/158/175https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/158/175http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/158/175https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/158/175https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/158/175http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/158/175GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap2.367228618189496e-19 3.3785437584409506e-19OpticalInfrareddefaultJ/AJ/158/175/table2The R and I magnitudes of the star AF And and their corresponding errors in each of the observed nightsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDobs[1/169] Observation serial numbermeta.idintmJDMid-Julian Day of observation (JD-2450000)dtime.epochdoubleRmag[15.896/17.343]? Apparent Cousins R band magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag[0.003/0.083]? Uncertainty in Rmagmagstat.error;phot.mag;em.opt.RfloatnullableImag[15.794/17.3]? Apparent Cousins I band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag[0.003/0.06]? Uncertainty in Imagmagstat.error;phot.mag;em.opt.IfloatnullableJ/AJ/158/175/spectraCombined table from original tablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintgrismGrism of observationmeta.id;instrcharWave[3608/8908] Wavelength ({AA}) (1)0.1nmem.wlintFlux[1.51015e-16/7.96979e-15] Flux (in erg/s/cm^2^/{AA}) (1)0.01W.m**-2.nm**-1phot.flux.density;em.optdoubleJ/AJ/158/175/table1Observing log of the dataTelTelescope code (ST or HCT)meta.code;instr.telcharCCDCCD usedinstr.fov;instr.pixelcharExpI[60/1200]? Exposure time in I bandstime.duration;obs.exposure;em.opt.IintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullablemJDMid-Julian Day of observationdtime.epochdoubleFWHM[0.71/3.32] PSF Full-Width at Half-Maximumarcsecphys.angSizefloatNR[1/47]? Number of R band framesmeta.numberintnullableExpR[60/1200]? Exposure time in R bandstime.duration;obs.exposure;em.opt.RintnullableNI[1/30]? Number of I band framesmeta.numberintnullableFoVField of Viewarcminphys.angSize;srcchar