J/ApJ/871/13ivo://CDS.VizieR/J/ApJ/871/13doi:10.26093/cds/vizier.18710013CDSBischoff-Kim A.Provencal J.L.Bradley P.A.Montgomery M.H.,Shipman H.L.Harrold S.T.Howard B.Strickland W.Chandler D.,Campbell D.Arredondo A.Linn R.Russell D.P.Doyle D.Brickhouse A.,Peters D.Kim S.-L.Jiang X.J.Mao Y.-N.Kusakin A.V.Sergeev A.V.,Andreev M.Velichko S.Janulis R.Pakstiene E.Alicavus F.Horoz N.,Zola S.Ogloza W.Koziel-Wierzbowska D.Kundera T.Jableka D.,Debski B.Baran A.Meingast S.Nagel T.Loebling L.Heinitz C.,Hoyer D.Bognar Z.Castanheira B.G.Erdem A.2021-06-18T13:44:20Z2020-02-25T13:35:08ZCDS support team

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

cds-question@unistra.frasteroseismologyccd-photometrywhite-dwarf-starsWe report on the analysis of 34 years of photometric observations of the pulsating helium atmosphere white dwarf GD358. The complete data set includes archival data from 1982 to 2006, and 1195.2hr of new observations from 2007 to 2016. From this data set, we extract 15 frequencies representing g-mode pulsation modes, adding 4 modes to the 11 modes known previously. We present evidence that these 15 modes are l=1 modes, 13 of which belong to a consecutive sequence in radial overtone k. We perform a detailed asteroseismic analysis using models that include parameterized, complex, carbon and oxygen core composition profiles to fit the periods. Recent spectroscopic analyses place GD358 near the red edge of the DBV instability strip, at 24000{+/-}500K and a logg of 7.8{+/-}0.08dex. The surface gravity translates to a mass range of 0.455-0.540M_{sun}_. Our best-fit model has a temperature of 23650K and a mass of 0.5706M_{sun}_. That is slightly more massive than what is suggested by the most recent spectroscopy. We find a pure helium layer mass of 10^-5.50^, consistent with the result of previous studies and the outward diffusion of helium over time.2019ApJ...871...13Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/871/13CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/wd : Spectroscopically identified white dwarfs (McCook+, 2014)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/317/689 : Hot subdwarfs proper motions (Thejll+ 1997)J/A+A/363/1040 : DB WDs from the Hamburg/ESO survey (Friedrich+, 2000)J/ApJ/631/1100 : Atmospheric parameters of DA white dwarfs (Gianninas+, 2005)J/ApJS/161/394 : Low-luminosity companions to white dwarfs (Farihi+, 2005)J/AJ/132/676 : SDSS hot DB white dwarfs (Eisenstein+, 2006)J/MNRAS/399/699 : Parameters of atmopsheres of white dwarfs (Mortlock+, 2009)J/A+A/548/A79 : INTEGRAL-OMC opt. variable sources (Alfonso-Garzon+, 2012)J/A+A/557/A19 : Mass & age of extreme low-mass white dwarfs (Althaus+, 2013)J/ApJ/794/35 : Binary white dwarfs atmospheric param. (Gianninas+, 2014)J/MNRAS/454/2787 : LAMOST DR2 white dwarfs (Guo+, 2015)J/A+A/583/A86 : DB white dwarfs in SDSS DR10 and DR12 (Koester+, 2015)J/A+A/595/A35 : Low-mass He white dwarfs evolutionary models (Istrate+,2016)J/ApJ/835/173 : Kepler asteroseismic LEGACY sample II. (Silva Aguirre+, 2017)J/ApJ/848/11 : Spectroscopic & photometric analysis of WDs (Bedard+, 2017)J/ApJS/232/23 : 27 pulsating DA WDs follow-up observations (Hermes+, 2017)J/MNRAS/472/4173 : Bright WDs for high-speed photometry (Raddi+, 2017)J/A+A/618/A113 : Spectropolarimetric survey of white dwarfs (Bagnulo+, 2018)J/ApJS/241/32 : OB stars from the LAMOST DR5 spectra (Liu+, 2019)http://www.physics.udel.edu/gp/darc/wet : Whole Earth Telescope (WET) home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/871/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/871/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/871/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/871/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/871/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/871/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/871/13/table1Journal of observationsObsIDObservation's run name (1)meta.id;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTelTelescope identifier (2)meta.id;instr.telcharInstDetector usedinstr.setup;instr.detcharObs[2007/2016] Year of the observationtime.epochExp[0.4/8.9] Length of observationhtime.expofloatJ/ApJ/871/13/freqCombined table from original tablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.Y[1982/2006] Year of the observationyrtime.epochintFreq[923/2379] FrequencyuHzem.freqdoublee_Freq[0.001/3.5] Uncertainty in FrequHzstat.errorfloatnullablePer[420/1083] Periodstime.periodfloatAmp[1/36] Amplitudemmagphot.magfloate_Amp[0.01/1.1] Uncertainty in Ampmmagstat.errorfloatS/N[2.4/119] Signal-to-noise ratiostat.snrfloat