J/PASP/118/1238ivo://CDS.VizieR/J/PASP/118/1238doi:10.26093/cds/vizier.61181238CDSThorstensen J.R.Lepine S.Shara M.2026-01-20T12:20:07Z2008-04-17T12:37:26ZCDS support team

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

cds-question@unistra.frvariable-starsradial-velocityinfrared-photometryvisible-astronomybroad-band-photometryproper-motionsRBS (ROSAT Bright Source) 0490 is a cataclysmic variable star (CV) with unusually strong emission lines. The strength of the emission lines has led to a suggestion that the object is intrinsically faint and correspondingly nearby (33pc), which, if true, would strongly affect estimates of the CV space density. Here we report astrometry, filter photometry, and time-series spectroscopy of this object. The astrometry gives an absolute parallax of 4.5+/-1.5mas and a relative proper motion of 102mas/yr. A Bayesian procedure gives a very uncertain distance estimate of d~300pc, and the small parallax alone implies d>133pc (at 2 standard deviations). The mean V magnitude is 17.4, which implies M_V_=10.9-5log[d/(200pc)], neglecting extinction. At 200pc, the space velocity would be over 90km/s with respect to the local standard of rest. The time-series spectroscopy shows a possible emission-line radial velocity period near 46 minutes. This would be unusually short for an orbital period, and it may represent some other clock in the system.2006PASP..118.1238Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/PASP/118/1238CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/PASP/118/1238https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/PASP/118/1238http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/PASP/118/1238https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/PASP/118/1238https://vizier.iucaa.in/viz-bin/votable?-source=J/PASP/118/1238http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/PASP/118/1238GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/PASP/118/1238/table2 (*Filter photometry (for 20 stars))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/PASP/118/1238/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/PASP/118/1238/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/PASP/118/1238/table2?GETtext/xml+votable180.050000true58.4835-16.86888890.005555555555555556Cone search capability for table J/PASP/118/1238/table6 (*Astrometric parameters for all the stars measured in the field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/PASP/118/1238/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/PASP/118/1238/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/PASP/118/1238/table6?GETtext/xml+votable180.050000true58.4825417-16.88177780.0055555555555555566/362933.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/PASP/118/1238?format=asciiOpticalInfrareddefaultJ/PASP/118/1238/table2*Filter photometry (for 20 stars)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSample[FV] Field stars (averages of two observations) or Variable star (two observations separately)meta.codecharRA_ICRSRight ascension (ICRS) (1)pos.eq.ra;meta.mainDEICRSDeclination (IRCS) (1)pos.eq.dec;meta.mainU-B? U-B colour indexmagphot.color;em.opt.U;em.opt.Bfloatnullablee_U-B? rms uncertainty on U-B (2)magstat.error;phot.color;em.opt.UfloatnullableB-VB-V colour indexmagphot.color;em.opt.B;em.opt.Vfloate_B-Vrms uncertainty on B-V (2)magstat.error;phot.color;em.opt.BfloatVmagV magnitudemagphot.mag;em.opt.Vfloate_Vmagrms uncertainty on Vmag (2)magstat.error;phot.magfloatV-IV-I colour indexmagphot.color;em.opt.V;em.opt.Ifloate_V-Irms uncertainty on V-I (2)magstat.error;phot.color;em.opt.VfloatJ/PASP/118/1238/table4Radial Velocities for RBS 490 ([TLS2006] J035410.31-165250.3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date of mid-exposuredtime.epochdoubleRVemmAverage velocity of H{beta}, HeI 5876, and HeI 6678km/sphys.veloc;pos.heliocentricintJ/PASP/118/1238/table6*Astrometric parameters for all the stars measured in the fieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[*] * for program star (RBS 490)meta.id;meta.maincharRAICRSRight ascension (ICRS, J2000)pos.eq.ra;meta.mainDEICRSDeclination (IRCS, J2000)pos.eq.dec;meta.mainWeight[0/1] Weight, 1 or 0, depending on whether the star is used as referencestat.weight;phys.atmol.weightintVmagV magnitudemagphot.mag;em.opt.Vfloatsigmarms deviation from the relative positions predicted by the best-fit parallax and proper motionmagstat.stdevintV-IV-I colour indexmagphot.color;em.opt.V;em.opt.IfloatplxRelative parallaxmaspos.parallax.trigfloate_plxrms uncertainty on plxmasstat.error;pos.parallaxfloatpmXProper motion along X (1)mas/yrpos.pm;pos.cartesian.xfloatpmYProper motion along Y (1)mas/yrpos.pm;pos.cartesian.yfloate_pmXrms uncertainty on pmX and pmYmas/yrstat.errorfloat