J/ApJ/823/49ivo://CDS.VizieR/J/ApJ/823/49doi:10.26093/cds/vizier.18230049CDSSandhaus P.H.Debes J.H.Ely J.Hines D.C.Bourque M.2020-08-07T08:05:31Z2016-09-21T07:36:43ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starsspectroscopyultraviolet-astronomystellar-massesThe search for transiting habitable exoplanets has broadened to include several types of stars that are smaller than the Sun in an attempt to increase the observed transit depth and hence the atmospheric signal of the planet. Of all spectral types, white dwarfs (WDs) are the most favorable for this type of investigation. The fraction of WDs that possess close-in rocky planets is unknown, but several large angle stellar surveys have the photometric precision and cadence to discover at least one if they are common. Ultraviolet observations of WDs may allow for detection of molecular oxygen or ozone in the atmosphere of a terrestrial planet. We use archival Hubble Space Telescope data from the Cosmic Origins Spectrograph to search for transiting rocky planets around UV-bright WDs. In the process, we discovered unusual variability in the pulsating WD GD 133, which shows slow sinusoidal variations in the UV. While we detect no planets around our small sample of targets, we do place stringent limits on the possibility of transiting planets, down to sub-lunar radii. We also point out that non-transiting small planets in thermal equilibrium are detectable around hotter WDs through infrared excesses, and identify two candidates.2016ApJ...823...49Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/823/49CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)I/329 : URAT1 Catalog (Zacharias+, 2015)I/322 : UCAC4 Catalog (Zacharias+, 2012)V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)J/A+A/560/A106 : NLTE spectral analysis of white dwarf G191-B2B (Rauch+, 2013)J/ApJS/204/5 : SDSS DR7 white dwarf catalog (Kleinman+, 2013)J/AJ/143/135 : Ages of A-K type stars in DEBRIS survey (Vican, 2012)J/ApJ/743/138 : Spectroscopic survey of bright white dwarfs (Gianninas+, 2011)J/ApJ/730/128 : Spectroscopy of DA WD from the SDSS-DR4 (Tremblay+, 2011)J/ApJ/712/585 : Apparent velocity measurements of DA WDs (Falcon+, 2010)J/ApJS/187/149 : StarCAT: STIS UV echelle spectra of stars (Ayres, 2010)J/A+A/505/441 : UVES/VLT spectra of white dwarfs (Koester+, 2009)J/AJ/135/1239 : Spectral distances to DA white dwarfs (Holberg+, 2008)J/AJ/135/1225 : Parameters of the local white dwarfs (Holberg+, 2008)J/A+A/470/1079 : UVES/VLT spectroscopy of white dwarfs (Voss+, 2007)J/ApJ/652/1554 : Iron in hot DA white dwarfs (Vennes+, 2006)J/ApJS/161/394 : Low-luminosity companions to white dwarfs (Farihi+, 2005)J/ApJS/147/145 : IUE low-dispersion spectra of white dwarfs (Holberg+, 2003)J/A+A/373/730 : The IUE Absolute Flux Scale (Gonzalez-Riestra+, 2001)J/ApJS/119/207 : IUE echelle spectra of hot white dwarfs (Holberg+, 1998)J/ApJS/61/569 : KPD UV-excess objects (Downes+, 1986)http://www.stsci.edu/hst/cos : COS websitehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/823/49https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/823/49http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/823/49https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/823/49https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/823/49http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/823/49GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/823/49/table3 (Short exposure COS observations (79 targets))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/823/49/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/823/49/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/823/49/table3?GETtext/xml+votable180.050000true131.413257822.95784690.005555555555555556Cone search capability for table J/ApJ/823/49/table2 (Properties of transit search targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/823/49/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/823/49/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/823/49/table2?GETtext/xml+votable180.050000true47.4496575-56.39705920.0055555555555555566/419 1890 2184 4458 4898 5118 5166 5190 5760 5927 6118 7257 7312 7483 7498 7606 7631 7672 8155 9165 9484 10504 10637 11027 11712 12541 12746 12901 12936 13327 13352 15816 16438 16451 16599 17685 18341 18549 18652 19428 19979 20100 20152 22675 23013 23151 23241 23495 23544 23789 24659 25276 25326 25792 25943 26258 26326 27338 27504 27594 27631 27742 28026 28183 28559 30465 31265 31290 31451 33514 33591 34310 34398 34975 35258 35376 35790 36469 36861 41157 43928 45632 45802 47047 48863https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/823/49?format=asciiUVdefaultJ/ApJ/823/49/table3Short exposure COS observations (79 targets)SimbadNameSimbad column added by the CDSmeta.idchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainNameTarget identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsDate of observation startstime.epochnullableExp[150/2475] Exposure timestime.duration;obs.exposureintCR[4952/339310] Median count rates**-1phot.count;em.UVdoubleGratingGrating identifierinstr.setupcharlambda[1291/1623] Central wavelength of Grating; in Angstroms0.1nmem.wl.centralintPIDProposal identifiermeta.id;obsintFileFile identifiermeta.id;meta.filechar_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/823/49/table4COS observations of the seven transit search targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDWD namemeta.id;meta.maincharJDStart date of the observation in Julian Day; column added by CDSdtime.epochdoubleObsDate of the Observation startstime.epochnullableExp[45/2985] Exposure timestime.duration;obs.exposureintCR[-30054/319872] Count ratect/sphot.count;em.UVdoubleGratingGrating identifierinstr.setupcharlambda[1055/3360] Grating central wavelength0.1nmem.wl.centralintPIDProposal identifiermeta.id;obsintFileFile namemeta.id;meta.filecharJ/ApJ/823/49/table2Properties of transit search targetsLCHST/COS LC Plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDWD name (as in table 4)meta.id;meta.maincharprimaryTeff[20900/60920] Effective temperatureKphys.temperature.effectiveintlogg[7.5/8.3] Surface gravitylog(cm.s**-2)phys.gravityfloatlogL[-1.7/0.8] Log of WD luminositylog(solLum)phys.luminosity;em.UVfloatMass[0.5/0.9] WD masssolMassphys.massfloatRad[0.01/0.02] WD radiussolRadphys.size.radiusfloatRi[0.1/0.7] R_PHZ,i_ value (1)AUphys.size.radiusfloatRo[0.2/3.4] R_PHZ,o_ value (1)AUphys.size.radiusfloatNobsNumber of HST/COS observations for this white dwarfmeta.numberintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main