J/A+AS/115/75ivo://CDS.VizieR/J/A+AS/115/75CDSCosta E.Loyola P.1998-02-25T15:25:49Z1998-02-25T16:25:41ZCDS support team

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

cds-question@unistra.frradio-sourcesquasarsOptical positions, relative to the International Reference Stars catalogue (IRS), and therefore in the system of the FK5, have been obtained for the optical counterparts of 35 extragalactic radio sources south of {delta}~+3deg. Many of these sources are being considered as possible Benchmark objects for the establishment of a quasi-inertial unified radio/optical reference frame. Precision levels better than 0.2" in both coordinates were achieved. A comparison with VLBI radio positions available for these sources is presented. We give evidence for a possible offset in RA between the radio and optical reference frames.1996A&AS..115...75Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/115/75CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/115/75https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/115/75http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/115/75https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/115/75https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/115/75http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/115/75GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+AS/115/75/table1 (Optical positions in the FK5 system of 35 extragalactic radio sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+AS/115/75/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+AS/115/75/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+AS/115/75/table1?GETtext/xml+votable180.050000true1.14867917-47.605497220.005555555555555556https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+AS/115/75?format=asciiRadiodefaultJ/A+AS/115/75/table2Comparison in the FK5 system with the radio positions of the NRL/USNO SurveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIAUIAU designation of the sourcemeta.id;meta.maincharDeltaRADifference with the VLBI radio position from the NRL/USNO Survey (Fey et al. 1994); NRL-CL (CL=this paper); Delta {alpha} cos {delta}arcsecpos.eq.ra;arith.difffloatDeltaDEDifference with the VLBI radio position from the NRL/USNO Survey (Fey et al. 1994); NRL-CL (CL=this paper); Delta {delta}arcsecpos.eq.dec;arith.difffloatJ/A+AS/115/75/table1Optical positions in the FK5 system of 35 extragalactic radio sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIAUIAU designation of the sourcemeta.id;meta.maincharRA2000Right ascension (2000)pos.eq.ra;meta.maine_RAs? Error on right ascension: {sigma}({alpha}cos{delta}) (1)arcsecstat.errorfloatnullableDE2000Declination signpos.eq.dec;meta.maine_DEs? Error on declination: {sigma}(cos{delta})(1)arcsecstat.errorfloatnullableDateEpoch of observationtime.epochnullableNotesNotesmeta.notechar