J/ApJ/894/53ivo://CDS.VizieR/J/ApJ/894/53doi:10.26093/cds/vizier.18940053CDSKosakowski A.Kilic M.Brown W.R.Gianninas A.2025-09-05T20:02:32Z2021-10-21T15:27:56ZCDS support team

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

cds-question@unistra.frwhite-dwarf-starschemically-peculiar-starsvisible-astronomyspectroscopyradial-velocitysurveysstellar-massesWe begin the search for extremely low mass (M<=0.3M_{sun}_, ELM) white dwarfs (WDs) in the southern sky based on photometry from the VST ATLAS and SkyMapper surveys. We use a similar color selection method as the Hypervelocity star survey. We switched to an astrometric selection once Gaia Data Release 2 became available. We use the previously known sample of ELM white dwarfs to demonstrate that these objects occupy a unique parameter space in parallax and magnitude. We use the SOAR 4.1m telescope to test the Gaia-based selection, and identify more than two dozen low mass white dwarfs, including six new ELM white dwarf binaries with periods as short as 2h. The better efficiency of the Gaia-based selection enables us to extend the ELM Survey footprint to the southern sky. We confirm one of our candidates, J0500-0930, to be the brightest (G=12.6mag) and closest (d=72pc) ELM white dwarf binary currently known. Remarkably, the Transiting Exoplanet Survey Satellite (TESS) full-frame imaging data on this system reveals low-level (<0.1%) but significant variability at the orbital period of this system (P=9.5hr), likely from the relativistic beaming effect. TESS data on another system, J0642-5605, reveals ellipsoidal variations due to a tidally distorted ELM WD. These demonstrate the power of TESS full-frame images in confirming the orbital periods of relatively bright compact object binaries.2020ApJ...894...53Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/894/53CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/350 : VLT Survey Telescope ATLAS (Shanks+, 2015)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJ/723/1072 : The ELM survey. I. Low-mass white dwarfs (Brown+, 2010)J/ApJ/743/138 : Spectroscopic survey of bright WDs (Gianninas+, 2011)J/ApJ/794/35 : Binary white dwarfs atmospheric param. (Gianninas+, 2014)J/ApJ/818/155 : The ELM survey. VII. 15 new ELM WD cand. (Brown+, 2016)J/A+A/595/A35 : Low-mass helium WDs evolutionary models (Istrate+, 2016)J/MNRAS/455/3413 : New white dwarf & subdwarfs in SDSS DR12 (Kepler+, 2016)J/ApJ/839/23 : Subdwarf A stars vs ELM WDs radial velocities (Brown+, 2017)J/MNRAS/469/3688 : CSS Periodic Variable Star Catalogue (Drake+, 2017)J/MNRAS/480/1547 : Full Evolutionary Sequences of Massive WDs (Lauffer+, 2018)J/MNRAS/475/2480 : Extremely-low mass white dwarf star (Pelisoli+, 2018)J/A+A/621/A38 : Gaia catalogue of hot subluminous stars (Geier+, 2019)J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/894/53https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/894/53http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/894/53https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/894/53https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/894/53http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/894/53GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/894/53/elmwds (Physical (Table 2) and orbital (Table 3) parameters of the new extremely low mass (ELM) white dwarf binaries identified in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/894/53/elmwds?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/894/53/elmwds?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/894/53/elmwds?GETtext/xml+votable180.050000true189.0820833-4.74386110.005555555555555556Cone search capability for table J/ApJ/894/53/targets (White dwarfs observed as part of our ATLAS+SkyMapper or Gaia parallax target selection (Tables B1-B4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/894/53/targets?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/894/53/targets?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/894/53/targets?GETtext/xml+votable180.050000true0.1710833-31.04606110.0055555555555555566/16447 16454 16460 16474 16478 16543 16562 16573 16587 16622 16654 16672 16842 16906 16910 16918 16932 16961 17028 17118 17127 17203 17229 17248 17291 17451 17491 17551 17572 17577 17579 18483 18497 21081 21238 22617 22690 22697 22739 24641 24658 24733 24894 24899 25215 25301 25337 25451 25486 25522 25531 25535 25540 25545 25548 25558 25577 25632 25653 25752 25779 25833 25836 25875 25888 25894 25899 25984 26150 26164-26165 26255 26343 26637-26638 26660 26687 26719 26727 26735-26736 26774 26777 26781 26839 26851 26869 26872 26910 26953 27010 27018 27437 30795 30933 31131 31159 31185 31197 31209 33283 34110 34378 34558 34650 34696 34723 35116 35226 35307 35311 35315 35318 35320 35569 35572 35633 35734 35869 35887 35904 35959 35980 36002 36043 36049 36133 36192 36338 36598 36637 36672 36704 36778 36919 36924 37021 37524 37576 38352 38746 38953 38965 38972 39057 39101 39438 39475 40216 40404-40405 40415 40940 40976 43454 43491 43506 43744 43864 43932 44251 44359 44430 44458 44467 44523 44631 44635 44643 44656 44698 44801 44803 44822 44836-44837 44839 44842 44898 44915 44921 44925-44926 44940 44996 45000 45010 45029-45030 45035 46527 46587 46707 46808 46812 46844 46901 46926 46966 47019 47025 47036 47065 47070 47097 48391-48392 48407 48435 48619 486341.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/894/53?format=asciiOpticaldefaultJ/ApJ/894/53/elmwdsPhysical (Table 2) and orbital (Table 3) parameters of the new extremely low mass (ELM) white dwarf binaries identified in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaGaia DR2 source identifiermeta.id;meta.mainANameShortened position based name used in this workmeta.idcharf_GaiaObject flag(s) (G1)meta.codecharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainGmag[12.6/20.5] Gaia G band magnitudemagphot.mag;em.optfloatPlx[-3.3/15.7]? Gaia DR2 Parallaxmaspos.parallaxfloatnullablee_Plx[0.03/2.1]? Uncertainty in Plxmasstat.error;pos.parallaxfloatnullableTeff[7520/45580] Surface effective temperatureKphys.temperature.effectiveinte_Teff[5/8080] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlogg[5/9.2] Surface gravity, log (1)log(cm.s**-2)phys.gravityfloate_logg[0/1.4] Uncertainty in logglog(cm.s**-2)stat.errorfloatMass[0.15/1.3]? White dwarf mass (not for Tables B2 and B4)solMassphys.massfloatnullablee_Mass[0.01/0.2]? Uncertainty in MasssolMassstat.error;phys.massfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharPer[0.088/0.7] Orbital perioddtime.perioddoublenullablee_Per[1e-05/0.004] Uncertainty in Perdstat.errordoublenullableK[138/368] Velocity semi-amplitudekm/sphys.velocfloatnullablee_K[6.6/39.4] Uncertainty in Kkm/sstat.errorfloatnullableM2[0.29/1] Binary component, minimum masssolMassmeta.code.multip;phys.mass;stat.minfloatnullablee_M2[0.03/0.21] Uncertainty in M2solMassstat.errorfloatnullabletmax[0.9/3.6]? Maximum gravitational wave merger timeGyrtime.epoch;stat.maxfloatnullablePCatDisplay SkyMapper DR1.1 (II/358) and VST ATLAS DR3 (II/350) data within 1"meta.ref.urlcharnullableVPRadial velocity interactive plotmeta.ref.urlcharnullableJ/ApJ/894/53/targetsWhite dwarfs observed as part of our ATLAS+SkyMapper or Gaia parallax target selection (Tables B1-B4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeTarget type: WDa=WDs observed via our ATLAS+SkyMapper selection (Table B1), sdA=sdA+ELM candidates (Table B2); WDg=WDs identified via our Gaia plx selection (Table B3), sdB=sdB stars (Table B4)src.classcharGaiaGaia DR2 source identifiermeta.id;meta.mainANameShortened position based name used in this workmeta.idcharf_GaiaObject flag(s) (G1)meta.codecharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainGmag[12.6/20.5] Gaia G band magnitudemagphot.mag;em.optfloatPlx[-3.3/15.7]? Gaia DR2 Parallaxmaspos.parallaxfloatnullablee_Plx[0.03/2.1]? Uncertainty in Plxmasstat.error;pos.parallaxfloatnullableTeff[7520/45580] Surface effective temperatureKphys.temperature.effectiveinte_Teff[5/8080] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlogg[5/9.2] Surface gravity, log (1)log(cm.s**-2)phys.gravityfloate_logg[0/1.4] Uncertainty in logglog(cm.s**-2)stat.errorfloatMass[0.15/1.3]? White dwarf mass (not for Tables B2 and B4)solMassphys.massfloatnullablee_Mass[0.01/0.2]? Uncertainty in MasssolMassstat.error;phys.massfloatnullablePCatDisplay SkyMapper DR1.1 (II/358) and VST ATLAS DR3 (II/350) data within 1"meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/894/53/tableb5Radial velocity data for the 6 new ELM WDs with well-constrained orbital periods, as well as for sdA J1425-0508recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintANameShortened position based name used in this workmeta.idcharHJD[7835.65/8546.81] Heliocentric Julian date, HJD-2450000dtime.epochdoubleHRV[-191.17/602.87] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[5.14/31.33] Uncertainty in HRVkm/sstat.errorfloat