J/ApJ/761/162ivo://CDS.VizieR/J/ApJ/761/162doi:10.26093/cds/vizier.17610162CDSHynes R.I.Wright N.J.Maccarone T.J.Jonker P.G.Greiss S.,Steeghs D.Torres M.A.P.Britt C.T.Nelemans G.2021-08-04T12:26:42Z2014-09-16T14:10:58ZCDS support team

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

cds-question@unistra.frstellar-spectral-typesvariable-starsstellar-distancesurveysx-ray-sourcesastronomical-object-identificationWe identify 69 X-ray sources discovered by the Galactic Bulge Survey (GBS) that are coincident with or very close to bright stars in the Tycho-2 catalog. Additionally, two other GBS sources are resolved binary companions to Tycho-2 stars where both components are separately detected in X-rays. Most of these are likely to be real matches, but we identify nine objects with large and significant X-ray-to-optical offsets as either detections of resolved binary companions or chance alignments. We collate known spectral types for these objects, and also examine Two Micron All Sky Survey colors, variability information from the All-Sky Automated Survey, and X-ray hardness ratios for the brightest objects. Nearly a third of the stars are found to be optically variable, divided roughly evenly between irregular variations and periodic modulations. All fall among the softest objects identified by the GBS. The sample forms a very mixed selection, ranging in spectral class from O9 to M3. In some cases, the X-ray emission appears consistent with normal coronal emission from late-type stars, or wind emission from early-types, but the sample also includes one known Algol, one W UMa system, two Be stars, and several X-ray bright objects likely to be coronally active stars or binaries. Surprisingly, a substantial fraction of the spectroscopically classified, non-coincidental sample (12 out of 38 objects) have late B or A type counterparts. Many of these exhibit redder near-IR colors than expected for their spectral type and/or variability, and it is likely that the X-rays originate from a late-type companion star in most or all of these objects.2012ApJ...761..162Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/761/162CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/322 : UCAC4 Catalogue (Zacharias+, 2012)III/265 : RAVE 3rd data release (Siebert+, 2011)I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)IV/25 : HD identifications for Tycho-2 stars (Fabricius+, 2002)I/276 : Tycho Double Star Catalogue (TDSC) (Fabricius+ 2002)I/259 : The Tycho-2 Catalogue (Hog+ 2000)III/182 : HDE Charts: positions, proper motions (Nesterov+ 1995)J/ApJS/210/18 : X-ray survey of the Galactic Bulge (CXOGBS) (Jonker+, 2014)J/ApJS/194/18 : The Galactic Bulge Survey: X-ray observations (Jonker+, 2011)J/ApJ/743/48 : Stellar rotation periods & X-ray luminosities (Wright+, 2011)J/ApJ/725/480 : Stellar X-ray sources in the COSMOS survey (Wright+, 2010)J/MNRAS/371/252 : Southern B and Be stars (Levenhagen+, 2006)J/A+A/460/695 : Associations Containing Young stars (Torres+, 2006)J/MNRAS/363/1111 : Tycho-2 stars with IR excess (Clarke+, 2005)J/ApJ/595/1206 : ROSAT view of Hipparcos F stars (Suchkov+, 2003)J/A+A/373/576 : Detection of Tycho variables stars (Piquard+, 2001)J/A+A/368/835 : Galactic Center region soft X-ray sources (Sidoli+, 2001)J/ApJ/315/687 : X-Ray emission from solar-type stars: F and G (Maggio+, 1987)J/AJ/80/972 : Dwarf K and M stars at low latitudes (Stephenson+, 1975)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/761/162https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/761/162http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/761/162https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/761/162https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/761/162http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/761/162GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/761/162/opt (ASAS counterparts to optically bright GBS Northern and Souhtern strip sources (tables 1, 2 and 3))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/761/162/opt?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/761/162/opt?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/761/162/opt?GETtext/xml+votable180.050000true264.8801-29.16480.0055555555555555565/7212 7213 6/28807 28816 28818 28819 28822 28823 28828 28829 28836 28837 28839 28866 28867 28872 28873 28898https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/761/162?format=asciiX-raydefaultJ/ApJ/761/162/optASAS counterparts to optically bright GBS Northern and Souhtern strip sources (tables 1, 2 and 3)CXOGBSCXOGBS identifier in GBS (Jonker et al. 2014, Cat. J/ApJS/210/18)meta.id;meta.maincharRefReference(s) (2)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXSource index number as in Jonker+, 2014, Cat. J/ApJS/210/18 (04-1219 and B5-B422); <CXOGBS JHHMMSS.s+DDMMSS> in Simbadmeta.idcharprimaryMmeta.ref.urlcharTYCTycho-2 number (Cat. I/259)meta.id.assoccharHD? HD identificationmeta.id.associntnullablem_HDHD multiplicity in case of binarymeta.code.multipcharSep[0/6.4] Offset between X-ray source and Tycho-2arcsecpos.angDistancefloatVmag[6.6/12.4] V-band magnitudemagphot.mag;em.opt.Vfloate_Vmag[0.01/0.4] Vmag uncertaintymagstat.error;phot.magfloat(B-V)[-0.3/2] B-V color indexmagphot.color;em.opt.B;em.opt.Vfloate_(B-V)[0.02/0.5] (B-V) uncertaintymagstat.errorfloatu_(B-V)[a] doubtful (B-V) (1)meta.code.errorcharlogF[-5.4/-2.2] log(F_X_/F_opt_)phot.flux;arith.ratiofloatSpTMK spectral typesrc.spTypecharnullableASASASAS identifier (HHMMSS+DDMM.m; J2000; Cat. II/264)meta.idcharVar[0.01/0.3] 68.2% variance of ASAS photometrymagstat.variancefloatPer[0.4/31.2]? Perioddtime.perioddoublenullablee_Per? Per uncertaintydstat.errordoublenullableCommCommentmeta.notechar_RAPositions from Tycho-2 (Cat. I/259) (right ascension part)degpos.eq.ra;meta.main_DEPositions from Tycho-2 (Cat. I/259) (declination part)degpos.eq.dec;meta.mainJ/ApJ/761/162/table4Distances and luminosities based on Hipparcos parallaxesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXGBS source numbermeta.idcharSpTMK spectral typesrc.spTypecharnullableE(B-V)[-0.06/0.08] B-V color excessmagphot.color.excessfloate_E(B-V)[0.03/0.05] E(B-V) uncertaintymagstat.errorfloatPlx[3.8/68] Hipparcos parallaxmaspos.parallaxfloate_Plx[0.5/45] Plx uncertaintymasstat.error;pos.parallaxfloatDist[15/260] Distancepcpos.distance;pos.heliocentricfloatE_Dist[1.5/170] Positive error on Distpcstat.error;stat.maxfloate_Dist[1.5/70] Negative error on Distpcstat.errorfloatLXX-ray luminosity1e-07Wphys.luminosity;em.X-raydoubleE_LXPositive error on LX1e-07Wstat.error;stat.maxdoublee_LXNegative error on LX1e-07Wstat.errordoubleCommCommentsmeta.notecharJ/ApJ/761/162/table5Distances and luminosities based on spectroscopic parallaxesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXGBS source numbermeta.idcharSpTMK spectral typesrc.spTypecharnullableE(B-V)[-0.3/0.9] B-V inferred color excessmagphot.color.excessfloate_E(B-V)[0.02/0.3] E(B-V) uncertaintymagstat.errorfloatf_E(B-V)[b] Flag on E(B-V)meta.codecharE(B-V)l[0.9/3.7] B-V line of sight color excessmagphot.color.excessfloate_E(B-V)l[0.2/0.5] E(B-V)l uncertaintymagstat.errorfloatDist[41/2800] Distancepcpos.distance;pos.heliocentricintLXX-ray luminosity1e-07Wphys.luminosity;em.X-raydoubleCommCommentsmeta.notechar