J/ApJ/922/33ivo://CDS.VizieR/J/ApJ/922/33doi:10.26093/cds/vizier.19220033CDSRoulston B.R.Green P.J.Toonen S.Hermes J.J.2023-08-25T12:29:09Z2023-04-25T08:40:13ZCDS support team

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

cds-question@unistra.frcarbon-starsinfrared-photometryvisible-astronomyWide-band photometrytrigonometric-parallaxstellar-distancestellar-radiistellar-massesDwarf carbon (dC) stars, main-sequence stars showing carbon molecular bands, are enriched by mass transfer from a previous asymptotic-giant-branch (AGB) companion, which has since evolved to a white dwarf. While previous studies have found radial-velocity variations for large samples of dCs, there are still relatively few dC orbital periods in the literature and no dC eclipsing binaries have yet been found. Here, we analyze photometric light curves from DR5 of the Zwicky Transient Facility for a sample of 944 dC stars. From these light curves, we identify 34 periodically variable dC stars. Remarkably, of the periodic dCs, 82% have periods less than two days. We also provide spectroscopic follow-up for four of these periodic systems, measuring radial velocity variations in three of them. Short-period dCs are almost certainly post-common-envelope binary systems, because the periodicity is most likely related to the orbital period, with tidally locked rotation and photometric modulation on the dC either from spots or from ellipsoidal variations. We discuss evolutionary scenarios that these binaries may have taken to accrete sufficient C-rich material while avoiding truncation of the thermally pulsing AGB phase needed to provide such material in the first place. We compare these dCs to common-envelope models to show that dC stars probably cannot accrete enough C-rich material during the common-envelope phase, suggesting another mechanism like wind-Roche lobe overflow is necessary. The periodic dCs in this paper represent a prime sample for spectroscopic follow-up and for comparison to future models of wind-Roche lobe overflow mass transfer.2021ApJ...922...33Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/922/33CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)V/156 : LAMOST DR7 catalogs (Luo+, 2019)V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)J/ApJS/151/387 : Near-IR spectral library of late-type stars (Ivanov+, 2004)J/AJ/134/2340 : Membership of Praesepe & Coma Ber clusters (Kraus+, 2007)J/ApJS/194/28 : The evolution of cataclysmic variables (Knigge+, 2011)J/ApJ/765/12 : Carbon stars & DQ WDs from SDSS-DR7+DR8 (Green, 2013)J/other/SCPMA/57.176 : Carbon stars & DZ white dwarfs in SDSS sp. (Si+ 2014)J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)J/A+A/586/A158 : Binary properties of CH and CEMP stars (Jorissen+, 2016)J/ApJS/231/1 : Hot DA WDs grid of synthetic spectra (Levenhagen+, 2017)J/MNRAS/479/5491 : Absolute parameters of 509 main-sequence stars (Eker+, 2018)J/AJ/155/252 : Astrometry & phot. of dwarf carbon stars (Harris+, 2018)J/AJ/155/225 : M dwarf stars rot. broadening measurements (Kesseli+, 2018)J/ApJS/234/31 : Carbon stars from LAMOST using machine learning (Li+, 2018)J/MNRAS/484/5362 : White dwarf+M dwarf binaries RVs (Ashley+, 2019)J/A+A/626/A128 : Main-sequence and subgiant Barium stars (Escorza+, 2019)J/AJ/157/63 : Radii for low-metallicity M-dwarf stars (Kesseli+, 2019)J/ApJ/877/44 : RV variability in SDSS dwarf carbon stars (Roulston+, 2019)J/ApJ/901/93 : Model atm. analysis of hot WDs from SDSS (Bedard+, 2020)J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/922/33https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/922/33http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/922/33https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/922/33https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/922/33http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/922/33GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/922/33/table5 (Periodic dC parallaxes, distances, and estimated physical parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/922/33/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/922/33/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/922/33/table5?GETtext/xml+votable180.050000true11.77816670.13022220.005555555555555556Cone search capability for table J/ApJ/922/33/table2 (34 individual periodic dwarf carbon (dC) light-curve properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/922/33/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/922/33/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/922/33/table2?GETtext/xml+votable180.050000true11.77816670.13022220.0055555555555555566/824 1426 1928 2289 4538 4645 5671 6983 9078 9269 9888 9909-9910 10741 10905 11030 11117 11178 11184 11196 11336 11360 13440 15113 17785 18026 19691 22198 25867 26281 26325 27283 31389 324911.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/922/33?format=asciiOpticalInfrareddefaultJ/ApJ/922/33/table5Periodic dC parallaxes, distances, and estimated physical parametersDist[106/4420] Distance from Bailer-Jones+ I/352pcpos.distance;pos.heliocentricinte_Dist[0/799] Dist uncertaintypcstat.errorint_RA.icrsRight ascension (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.decindexedBP-RP[0.69/2.15] Gaia EDR3 BP-RP color indexmagphot.color;em.opt.B;em.opt.RfloatGmag[5.67/10.38] Gaia EDR3 G-band magnitudemagphot.mag;em.optfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSHour of right ascension (ICRS) at Epoch=2016.0pos.eq.ra;meta.mainDE_ICRSDegree of declination (ICRS) at Epoch=2016.0pos.eq.dec;meta.mainplx[0.1/9.54] Gaia EDR3 parallaxmaspos.parallax.trigfloate_plx[0.015/0.4] Parallax uncertaintymasstat.error;pos.parallaxfloatKMag[3.9/6.82] 2MASS absolute K band magnitudemagphys.magAbsfloatf_KMagc=KMag interpolated from Gmagmeta.codecharMass[0.25/0.9] Mass (1)solMassphys.massfloatlogLbol[-1.96/-0.34] Log of bolometric luminosity in erg/s (1)log(1e-07W)phys.luminosityfloatRad[0.22/0.86] Radius (1)solRadphys.size.radiusfloatRLFF[0.05/1.6] Roche-lobe filling factor (2)phys.volume;arith.ratiofloatG13Display data from Green P. 2013, J/ApJ/765/12 if anymeta.ref.urlintnullableNpNumber of photometric measurements (link to Table 2)meta.ref.urlintnullableGaiaDisplay data from Gaia EDR3 (I/350) and DR3 (I/355) within 3"meta.ref.urlchar2MDisplay the 2MASS data (II/246) within 3"meta.ref.urlcharJ/ApJ/922/33/table234 individual periodic dwarf carbon (dC) light-curve propertiesFilt[gri] Filtermeta.id;instr.filterchar_RA.icrsRight ascension (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.raindexedN[20/1281] N_good_ valuemeta.numberintNrej[0/10] N_rejects_ valuemeta.numberintmag[13.5/21.1] Mean magnitude in Filtmagphot.magfloate_mag[0.01/0.21] Uncertainty on magmagstat.error;phot.magfloatPer[0.13/13.6] Best perioddtime.period;meta.modelleddoublee_Per[1e-05/0.011] Per uncertaintydstat.errordoublel_logFAPLimit flag on FAPmeta.code.errorcharlogFAP[-238.8/-1] log of false-alarm probability for the periodstat.fit.goodnessfloatAmp[0.004/0.5] Amplitude of variability from the best-fit model at the periodmagsrc.var;meta.modelledfloate_Amp[0.003/0.21] Amp uncertaintymagstat.errorfloatt0[58627.9/59234.5] Time of light-curve maximum brightnessdtime.epochdoublee_t0[0.00013/0.03] t0 uncertaintydstat.errordoubleNt[1/6] Number of terms in our model fitmeta.numberintChi2[0.55/20.78] Reduced {chi}^2^ of the modelstat.param;meta.modelledfloat_DE.icrsDeclination (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPDisplay the estimated physical parameters (link to Table 5)meta.ref.urlintnullableSeq[1/90] Running sequence numbermeta.id;meta.mainintu_Seq[*d ] Flag(s) on Seq (1)meta.code.errorcharRA_ICRSHour of right ascension (ICRS) at Epoch=2016.0pos.eq.ra;meta.mainDE_ICRSDegree of declination (ICRS) at Epoch=2016.0pos.eq.dec;meta.main