J/A+A/551/A31ivo://CDS.VizieR/J/A+A/551/A31doi:10.26093/cds/vizier.35510031CDSDrilling J.S.Jeffery C.S.Heber U.Moehler S.Napiwotzki R.2018-01-08T06:38:07Z2013-02-14T08:52:20ZCDS support team

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

cds-question@unistra.frearly-type-starssubdwarf-starsmorgan-keenan-classificationAn MK (Morgan-Keenan)-like system of spectral classification for hot subdwarfs is presented. We find that a three-dimensional spectral type, consisting of a 'spectral' class, a 'luminosity' class, and a 'helium' class, is necessary to classify the sdO (subdwarf O) and sdB (subdwarf B) stars. In addition, the helium-strong stars appear to form two parallel spectral sequences: one showing strong lines of CII, CIII, or CIV, and the other with these same lines weak or absent. We also give a preliminary calibration of the new spectral types in terms of effective temperature, surface gravity, and surface helium-to-hydrogen abundance ratio, and show the relation between the new spectral types and the natural groups defined by the PG (Palomar-Green) survey.2013A&A...551A..31Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/551/A31CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/137 : Spectroscopically Identified Hot Subdwarf Stars (Kilkenny+ 1988)J/A+A/317/689 : Hot subdwarfs proper motions (Thejll+ 1997)J/AJ/126/1455 : 2MASS photometry of hot subdwarf stars (Stark+, 2003)J/AJ/138/606 : Hot subdwarf stars in rejected PG catalog (Wade+, 2009)J/A+A/530/A28 : New hot subdwarf stars (Oreiro+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/551/A31https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/551/A31http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/551/A31https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/551/A31https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/551/A31http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/551/A31GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/551/A31/table1 (Standard stars defining the new system)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/551/A31/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/551/A31/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/551/A31/table1?GETtext/xml+votable180.050000true207.566583360.41066670.005555555555555556Cone search capability for table J/A+A/551/A31/table2 (Spectral types for all stars in our sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/551/A31/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/551/A31/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/551/A31/table2?GETtext/xml+votable180.050000true0.981683327.81040560.0055555555555555566/43 136 215 226 398 418 2073 4123 4285 4293 4297 4319 4390 4481 4938 4976 5724 5843 7384 8518 8521 8570 8707 8791 8830 9100 9285 9330 9516 9633 9664 9683 9690 9720 9790 9811 9827 9853 9855 9908 9959 9981 10017 10048 10088 10123 10126 10132 10144 10159 10189 10214 10216 10322 10379 10471 10584 10715 10945 11157 11264 11303 11335 11509 11541 11560 11593 11599 11616 11652 11680 11704 11786 11802 12023 12289 12355 13480 14365 16010 17726 17864 18098 18132 18302 18372 18391 18712 18774 18900 18906 18941 19068 19071 19121 19130 19159 19210 19280 19290 19350 19361 19371-19372 19392 19436 19475 19590 19649 19666 19710 19726 19741 20002 20014 20055 20059 20165 20184 20207 20259 20279 23244 23395 25076 25469 25545 25700 25719 25740 25751 25845 25957 25990 26112 26138 26184 26351 26416 26748 26854 26959 27000 27045 27056 27099 27126 27324 27350 27844 29122 29300 30895 31269 31290 31332 31339 31346 31437 31444 31488 31491 31550 31622 31796 32293 32458 32476 32502 32674 36770 44798 44879 44986 44994 45011 45027 48933https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/551/A31?format=asciiOpticaldefaultJ/A+A/551/A31/indexSummary of spectra in spectrum subdirectoryspPlot of spectrummeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileNameSpectrum file name in subdirectory spectrummeta.id;meta.filecharN[692/6888] Number of records in spectrum filemeta.numberintSSimbad column added by the CDSmeta.notecharNameStar name (as in table 2)meta.id;meta.maincharlam0[3461/4572] Lower limit of wavelength range ({AA})0.1nminstr.bandwidthintlam1[4612/5531] Upper limit of wavelength range ({AA})0.1nminstr.bandwidthintJ/A+A/551/A31/table1Standard stars defining the new systemrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintASimbad column added by the CDSmeta.ref.urlcharNameStar namemeta.id;meta.maincharBmagB magnitudemagphot.mag;em.opt.Bfloatu_BmagUncertainty flag on Bmagmeta.code.errorcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainNspNumber of spectra for this starmeta.numberintnullableSpTypeMK Spectral typesrc.spTypecharJ/A+A/551/A31/table2Spectral types for all stars in our sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintASimbad column added by the CDSmeta.ref.urlcharSSimbad column added by the CDSmeta.notecharNameStar namemeta.id;meta.maincharprimaryn_NameIndividual note (1)meta.notecharNspNumber of spectra for this starmeta.numberintnullableSpTypeMK Spectral typesrc.spTypechar_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.mainJ/A+A/551/A31/table3Atmospheric parameters used in the calibrationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSSimbad column added by the CDSmeta.notecharNameStar namemeta.id;meta.maincharRefReference (1)meta.ref;pos.frameintTeffEffective temperaturekKphys.temperature.effectivefloatloggSurface gravitylog(cm.s**-2)phys.gravityfloatlog(He/H)[-4/2] Helium abundance (log[N(He)/N(H)]phys.abund.YfloatSpTypeMK spectral typesrc.spTypecharComCommentsmeta.notechar