J/ApJ/915/13ivo://CDS.VizieR/J/ApJ/915/13doi:10.26093/cds/vizier.19150013CDSSmith M.A.Henry G.W.2023-03-20T14:23:30Z2023-01-16T15:39:29ZCDS support team

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

cds-question@unistra.frvisible-astronomyWide-band photometrybe-stars{gamma} Cassiopeiae (B0.5IVe) is the noted prototype of a subgroup of classical Be stars exhibiting hard thermal X-ray emission. This paper reports results from a 23yr optical campaign on this star with an automated photometric telescope (APT). A series of unstable long cycles of length 56-91days has nearly ceased over the last decade. Also, we revise the frequency of the dominant coherent signal at 0.82238/days. This signal's amplitude has nearly disappeared in the last 15yr but has somewhat recovered its former strength. We confirm the presence of secondary nonradial pulsation signals found by other authors at frequencies 1.24, 2.48, and 5.03days^-1^. The APT data from intensively monitored nights reveal rapidly variable amplitudes among these frequencies. We show that peculiarities in the 0.82days^-1^ waveform exist that can vary even over several days. Although the 0.82days^-1^ frequency is near the star's presumed rotational frequency, because of its phase slippage with respect to a dip pattern in its far-UV light curve, it is preferable to consider the UV pattern, not the 0.82days^-1^ signal, as associated with rotational modulation. We also find hints of the UV dip pattern in periodograms of seasonal data early in our program.2021ApJ...915...13Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/915/13CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/647/1375 : BV light curves of {gamma} Cas (Smith+, 2006)J/ApJ/686/1280 : Discovery of hot subdwarf companion to FY CMa (Peters+, 2008)J/ApJ/760/10 : BV light curves of {gamma} Cas (1997-2011) (Henry+, 2012)J/A+A/537/A59 : Radial velocities of gamma Cas (Nemravov+, 2012)J/A+A/540/A53 : {gamma} Cas radial velocity curve (Smith+, 2012)J/ApJ/765/2 : FUV radial velocities of 59 Cyg (Peters+, 2013)J/A+A/613/A70 : Be stars in the exofield of CoRoT. II. (Semaan+, 2018)J/A+A/640/A36 : OB stars TESS phot. & high-res. spectroscopy (Bowman+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/915/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/915/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/915/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/915/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/915/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/915/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/915/13/table1Photometric observations of {gamma} Cas for seasons 1997-2019recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[50718.69/58888.6] Reduced Julian Date; HJD-2400000)dtime.epochdoubleVarB[-4.4/-4.2]? Variable - Comparison (HD 6210) differential magnitude in B (1)magphot.mag;arith.diff;em.opt.BfloatnullableVarV[-3.8/-3.6]? Variable - Comparison (HD 6210) differential magnitude in V (1)magphot.mag;arith.diff;em.opt.VfloatnullableChkB[-0.83/-0.78]? Check (HD 5395) - Comparison differential magnitude in B (1)magphot.mag;arith.diff;em.opt.BfloatnullableChkV[-1.25/-1.19]? Check (HD 5395) - Comparison differential magnitude in V (1)magphot.mag;arith.diff;em.opt.Vfloatnullable