J/ApJ/510/659ivo://CDS.VizieR/J/ApJ/510/659doi:10.26093/cds/vizier.15100659CDSPeterson B. M.Barth A. J.Berlind P.Bertram R.Bischoff K.,Bochkarev N. G.Burenkov A. N.Cheng F.-Z.Dietrich M.,Pilippenko A. V.Giannuzzo E.Ho L. C.Huchra J. P.Hunley J.,Kaspi S.Kollatschny W.Leonard D. C.Malkov Y. F.Matheson T.,Mignoli M.Nelson B.Papaderos P.Peters J.Pogge R. W.,Pronik V. I.Sergeev S. G.Sergeeva E. A.Shapovalova A. I.,Stirpe G. M.Tokarz S.Wagner R. M.Wanders I.Wei J.-Y.,Wilkes B. J.Wu H.Xue S.-J.Zou Z.-L.2000-02-22T08:32:07Z2000-02-22T09:31:35ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleigalaxiesvisible-astronomyseyfert-galaxiesphotometryWe present the results of 3 yr of ground-based observations of the Seyfert 1 galaxy NGC 5548, which, combined with previously reported data, yield optical continuum and broad-line H{beta} light curves for a total of 8 yr. The light curves consist of over 800 points, with a typical spacing of a few days between observations. During this 8 yr period, the nuclear continuum has varied by more than a factor of 7, and the H{beta} emission line has varied by a factor of nearly 6. The H{beta} emission line responds to continuum variations with a time delay or lag of {=~}10--20 days, the precise value varying somewhat from year to year. We find some indications that the lag varies with continuum flux in the sense that the lag is larger when the source is brighter.1999ApJ...510..659Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/510/659CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/115/185 : 3C 390.3 BVRI and H photometry (Dietrich+, 1998)J/A+A/371/79 : NGC 5548 UBVRI phot., Halpha & Hbeta fluxes (Dietrich+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/510/659https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/510/659http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/510/659https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/510/659https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/510/659http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/510/659GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/510/659/table4Optical continuum and H{beta} light curvesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intJDJulian Date (-2440000.0)ddoubleF5100Flux at 5100{AA} (10^-15 erg/cm^2/s/{AA})1e-14mW.m**-2.nm**-1floate_F5100uncertainty of F5100 (10^-15 erg/cm^2/s/{AA})1e-14mW.m**-2.nm**-1floatFHbetaFlux at H{beta} (10^-13 erg/cm^2/s/{AA})1e-12mW.m**-2.nm**-1floate_FHbetauncertainty of FHbeta (10^-13 erg/cm^2/s/{AA})1e-12mW.m**-2.nm**-1float