J/A+A/395/11ivo://CDS.VizieR/J/A+A/395/11doi:10.26093/cds/vizier.33950011CDSTosti G.Massaro E.Nesci R.Ciprini S.Nucciarelli G.Maesano M.,Montagni F.Raiteri C.M.Villata M.Lanteri L.Ostorero L.2017-06-21T08:22:24Z2003-04-22T22:57:41ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsinfrared-photometryvisible-astronomybroad-band-photometrykron-cousins-photometryWe present the results of the optical monitoring of the BL Lac object ON 231 from 1997 to the spring 2001, including the large outburst of spring 1998. After this event the mean source luminosity declined slowly and continued to show changes greater than one magnitude. A simple analysis of the variability time scales in the best-sampled segments of the light curve reveals that the luminosity changes were faster during the burst and slowed down in the subsequent years.2002A&A...395...11Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/395/11CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/356/L21 : BR photometry of ON 231 (Belokon+, 2000)J/A+AS/130/109 : BV(RI)c photometry of ON 231 (Tosti+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/395/11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/395/11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/395/11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/395/11https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/395/11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/395/11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+A/395/11/table2BVRI photometry, from March 1997 to June 2001recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUTC Datetime.epochnullableHJDHeliocentric Julian Datedtime.epochdoubleBmag? B (Johnson) magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag? B (Johnson) magnitude errormagstat.errorfloatnullableVmag? V (Johnson) magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag? V (Johnson) magnitude errormagstat.errorfloatnullableRcmag? R (Cousins) magnitudemagphot.mag;em.opt.Rfloatnullablee_Rcmag? R (Cousins) magnitude errormagstat.errorfloatnullableIcmag? I (Cousins) magnitudemagphot.mag;em.opt.Ifloatnullablee_Icmag? I (Cousins) magnitude errormagstat.errorfloatnullableObsOrigin of data (1)meta.id;instr.obstychar