J/A+A/611/A52ivo://CDS.VizieR/J/A+A/611/A52doi:10.26093/cds/vizier.36110052CDSTaris F.Damljanovic G.Andrei A.Souchay J. KlotzA.Vachier F.2018-05-16T07:14:12Z2018-03-23T08:22:53ZCDS support team

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

cds-question@unistra.frquasarsinfrared-photometryvisible-astronomyphotometryThe first release of the Gaia catalog is available since 14 September 2016. It is a first step in the realization of the future Gaia reference frame. This reference frame will be materialized by the optical positions of the sources and will be compared with and linked to the International Celestial Reference Frame, materialized by the radio position of extragalactic sources. As in the radio domain, it can be reasonably postulated that quasar optical flux variations can alert us to potential changes in the source structure. These changes could have important implications for the position of the target photocenters (together with the evolution in time of these centers) and in parallel have consequences for the link of the reference systems. A set of nine optical telescopes was used to monitor the magnitude variations, often at the same time as Gaia, thanks to the Gaia Observation Forecast Tool. The Allan variances, which are statistical tools widely used in the atomic time and frequency community, are introduced.2018A&A...611A..52Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/611/A52CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/323 : International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)I/337 : Gaia DR1 (Gaia Collaboration, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/611/A52https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/611/A52http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/611/A52https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/611/A52https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/611/A52http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/611/A52GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/611/A52/list (List of observed QSOs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/611/A52/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/611/A52/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/611/A52/list?GETtext/xml+votable180.050000true2.629191110.97486250.0055555555555555566/2549 4733 4923 5065 5072 5268 5306 5336 5637 5648 6067 6244 6519 6764 7896 8578 8673 8915 8918 9402 9796 10148 10198 10202 10280 10938 10978 11209 11557 11703 11765 11991 13092 13175 13664 13705 15100 15271 15306 16323 18027 19271 19567 19803 19831 20184 22659 23369 27717 28454 28517 28575 32261 32621 32715 38383 40479 45409 47014https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/611/A52?format=asciiInfraredOpticaldefaultJ/A+A/611/A52/table3List of observations in R filter from 2013 to 2016recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsTarget name (1)meta.idcharJDJulian date of observationtime.epochdoubleRmagR magnitudemagphot.mag;em.opt.Rfloate_Rmagrms uncertainty of the magnitude determinationmagstat.error;phot.mag;em.opt.RfloatJ/A+A/611/A52/listList of observed QSOsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameQSO name (IERS BHHMM+DDd)meta.id;meta.maincharOCATarget name for OCA observation in table3meta.idcharo_OCA? Number of OCA measuements in table3meta.numberintnullableTJOTarget name for TJO observation in table3meta.idcharo_TJO? Number of TJO measuements in table3meta.numberintnullableVBRLTarget name for VBRL observation in table3meta.idcharo_VBRL? Number of VBRL measuements in table3meta.numberintnullableLCShow the light curvesmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_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.main