J/ApJ/707/L114ivo://CDS.VizieR/J/ApJ/707/L114doi:10.26093/cds/vizier.17079114CDSGillessen S.Eisenhauer F.Fritz T.K.Bartko H.Dodds-Eden K.,Pfuhl O.Ott T.Genzel R.2026-05-19T14:24:40Z2012-02-02T15:05:33ZCDS support team

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

cds-question@unistra.frastrometryradial-velocitymilky-way-galaxymultiple-starsTwo recent papers (Ghez et al. 2008ApJ...689.1044G; Gillessen et al. 2009ApJ...692.1075G) have estimated the mass of and the distance to the massive black hole (MBH) in the center of the Milky Way using stellar orbits. The two astrometric data sets are independent and yielded consistent results, even though the measured positions do not match when simply overplotting the two sets. In this Letter, we show that the two sets can be brought to excellent agreement with each other when we allow for a small offset in the definition of the reference frame of the two data sets. The required offsets in the coordinates and velocities of the origin of the reference frames are consistent with the uncertainties given in Ghez et al. The so-combined data set allows for a moderate improvement of the statistical errors of the mass of and the distance to Sgr A*, but the overall accuracies of these numbers are dominated by systematic errors and the long-term calibration of the reference frame.2009ApJ...707L.114Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/707/L114CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/55 : A catalogue of high-velocity stars (Roman, 1955)J/ApJ/699/186 : VLA observations of the Galactic center (Zhao+, 2009)J/ApJ/697/1741 : Warped disks of YSOs in Galactic center (Bartko+, 2009)J/ApJ/681/1254 : Radial velocities of stars in the Galactic Center (Zhu+, 2008)J/ApJ/659/1241 : Stellar variability in Galactic Center (Rafelski+, 2007)J/AJ/127/3399 : Sgr A* variability at cm wavelengths (Herrnstein+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/707/L114https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/707/L114http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/707/L114https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/707/L114https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/707/L114http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/707/L114GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/707/L114/table1Orbital data for S2 used in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEp.AYear of the astrometric observationyrtime.epochdoubleoRAOffset in Right Ascension relative to SgrA*maspos.eq.ra;arith.difffloate_oRAUncertainty in oRAmasstat.errorfloatoDEOffset in Declination relative to SgrA*maspos.eq.dec;arith.difffloate_oDEUncertainty in oDEmasstat.errorfloatTel.ATelescope used in astrometric observationmeta.id;instr.telcharEp.V? Year of the radial velocity observationyrtime.epochdoublenullableVLSR? Local Standard of Rest Velocitykm/sphys.veloc;pos.lsrintnullablee_VLSR? Uncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrintnullableTel.VTelescope used in radial velocity observation (VLT or Keck)meta.id;instr.telchar