J/A+A/703/A259ivo://CDS.VizieR/J/A+A/703/A259CDSVince O.Raiteri C.M.Villata M.Gupta A.C.Kovacevic-Dojcinovic J.,Lakicevic M.Popovic L.C.Kushwaha P.Mirzaqulov D.O.Ehgamberdiev S.A.,Carosati D.Jorstad S.G.Marscher A.P.Weaver Z.R.Webb J.R.,Smith P.S.Chen W.Tsai A.Lin H.Borman G.A.Grishina T.S.,Hagen-Thorn V.A.Kopatskaya E.N.Larionova E.G.Larionov V.M.,Larionova L.V.Morozova D.A.Savchenko S.Troitskiy I.S.,Troitskaya Y.V.Vasilyev A.Zhovtan A.V.Shishkina E.V.Kurtanidze O.M.,Nikolashvili M.G.Kurtanidze S.O.Ivanidze R.Acosta-Pulido J.A.,Carnerero M.I.Damljanovic G.Stojanovic M.Jovanovic M.D.Vlasyuk V.,Spiridonova O.I.Moskvitin A.S.Pursimo T.Elsasser D.Feige M.,Kunkel L.Ledermann J.Reinhart D.Scherbantin A.Schoch K.,Steineke R.Lorey C.Agudo I.Escudero Pedrosa J.Aceituno F.J.,Bonnoli G.Casanova V.Morcuende D.Sota A.Bozhilov V.Valcheva A.,Zaharieva E.Minev M.Strigachev A.Bachev R.Mihov B.,Slavcheva-Mihova L.Sadun A.C.Takey A.Shokry A.El-Sadek M.A.,Marchini A.Verna G.2026-03-02T06:25:50Z2025-12-01T09:50:36ZCDS support team

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

cds-question@unistra.frquasarsphotometryvisible-astronomyWe analyze the optical variability of the flat-spectrum radio quasar (FSRQ) Ton 599 using BVRI photometry from the WEBT Collaboration (2011-2023), complemented by Steward Observatory monitoring. The study characterizes flux distributions, intranight changes, color evolution, and spectra to constrain physical parameters and processes in the central engine. We test flux distributions against normal and log-normal models, derive power spectral densities (PSDs), quantify intranight variability, and estimate emitting region sizes and magnetic fields from variability timescales. Long-term behavior is investigated by segmenting the light curves into 12 intervals, and color evolution is traced through color-magnitude and color-time diagrams. MgII line properties from low-flux spectra provide a black hole mass estimate. Ton 599 shows strong optical variability with log-normal flux distributions, red-noise PSDs, positive rms-flux relations, intranight variability, and a redder-when-brighter to bluer-when-brighter evolution depending on flux state. The peak R-band flux reaches 23.5mJy (log{nu}L{nu}=48.48[erg/s]). The estimated black hole mass is of order 10^8^M_{sun}_, consistent with previous studies.2025A&A...703A.259Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/703/A259CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/703/A259https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/703/A259http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/703/A259https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/703/A259https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/703/A259http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/703/A259GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/703/A259/photTon 599 BRVI photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBand[BVRI] Bandinstr.bandpasscharJDJulian Datedtime.epochdoubleindexedmagMagnitude in Band (1)magphot.magfloate_magError in magnitude in Bandmagstat.error;phot.magfloatObservObservatory code (2)meta.code;instr.obstychar