J/A+AS/119/281ivo://CDS.VizieR/J/A+AS/119/281CDSCutispoto G.1997-12-09T18:16:43Z1997-12-09T19:16:40ZCDS support team

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

cds-question@unistra.frvariable-starsinfrared-photometryvisible-astronomyWide-band photometrykron-cousins-photometryHigh-precision UBV(RI)_c_ photometry of 12 selected active stars, collected at the European Southern Observatory (La Silla, Chile) over the period February-March 1990, is presented. Significant evolution of the light curves, period variations and, in most cases, evidence for long-term variability of the global degree of spottedness are found. Some of the spectral classifications are discussed. This paper is part of a more extensive program focusing on the global properties and evolution of active stars and is aimed at establishing a time-extended photometric database which can give important clues on topics such as the stability of the spotted areas, differential rotation and solar-like cycles. For a description of the UBV and (RI)c photometric systems, see e.g. General Catalog of Photometric Data <GCPD/01> and <GCPD/54>.1996A&AS..119..281Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/119/281CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/121/369 : UBVRI observations of active stars. VI. (Cutispoto, 1997)J/A+AS/127/207 : UBV(RI)c photometry of active stars. VII. (Cutispoto, 1998)J/A+AS/131/321 : UBV(RI)c photometry of active stars. VIII. (Cutispoto, 1998)J/A+A/367/910 : UBV(RI)c photometry of active stars. IX. (Cutispoto+, 2001)J/A+A/400/659 : UBV(RI)c photometry of active stars. X (Cutispoto+, 1003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/119/281https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/119/281http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/119/281https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/119/281https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/119/281http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/119/281GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+AS/119/281/tableUBVRI photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDHD numbermeta.id;meta.maincharNameOther namemeta.idcharDateObservation periodtime.epochcharHJDHeliocentric Julian daydtime.epochdoublePhase[0/1[ Corresponding phase (1)time.phasefloatVmagV magnitudemagphot.mag;em.opt.VfloatU-B? U-B color indexmagphot.color;em.opt.U;em.opt.BfloatB-VB-V color indexmagphot.color;em.opt.B;em.opt.VfloatV-RcV-R_c_ color indexmagphot.color;em.opt.V;em.opt.RfloatV-IcV-I_c_ color indexmagphot.color;em.opt.V;em.opt.Ifloat