J/A+A/310/384ivo://CDS.VizieR/J/A+A/310/384doi:10.26093/cds/vizier.33100384CDSGreiner J.Danner R.Bade N.Richter G.A.Kroll P.Komossa S.1997-12-09T16:42:09Z1997-12-09T17:42:06ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleigalaxiesvisible-astronomyphotometryThe printed version of this paper describes the X-ray and optical properties of four new active galaxies discovered in the ROSAT All-Sky Survey. While one object (RX J1257.5+2412) is identified as a BL Lac object, the other three (RX J1239.3+2431, RX J1225.7+2055, and RX J1250.2+1923) are narrow line Seyfert 1 galaxies. Three of these four objects are bright enough to be studied on archival photographic plates of Sonneberg Observatory. The present list contains the individual brightness measurements of these objects all of which turned out to be variable on timescales of weeks to years. Some lightcurves (long-term as well as short-term) are given in the printed version.1996A&A...310..384Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/310/384CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/310/384https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/310/384http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/310/384https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/310/384https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/310/384http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/310/384GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapROSATOpticaldefaultJ/A+A/310/384/tableOptical brightness estimatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDJulian date of middle of exposure time. The exposure time ranges between 40-60 min.dtime.epochdoubleMag1? Brightness estimate for RX J1225.7+2055magphot.magfloatn_Mag1Comment on accuracy of brightness estimate of RX J1225.7+2055 (1)meta.notecharMag2? Brightness estimate for RX J1257.5+2412magphot.magfloatn_Mag2Comment on accuracy of brightness estimate of RX J1257.5+2412 (1)meta.notecharMag3? Brightness estimate for RX J1239.3+2431magphot.magfloatn_Mag3Comment on accuracy of brightness estimate of RX J1239.3+2431 (1)meta.notechar