J/MNRAS/402/2087ivo://CDS.VizieR/J/MNRAS/402/2087doi:10.26093/cds/vizier.74022087CDSVillforth C.Nilsson K.Heidt J.Takalo L.O.Pursimo T.Berdyugin A.,Lindfors E.Pasanen M.Winiarski M.Drozdz M.Ogloza W.,Kurpinska-Winiarska M.Siwak M.Koziel-Wierzbowska D.Porowski C.,Kuzmicz A.Krzesinski J.Kundera T.Wu J.-H.Zhou X.Efimov Y.,Sadakane K.Kamada M.Ohlert J.Hentunen V.-P.Nissinen M.,Dietrich M.Assef R.J.Atlee D.W.Bird J.DePoy D.L.Eastman J.,Peeples M.S.Prieto J.Watson L.Yee J.C.Liakos A.Niarchos P.,Gazeas K.Dogru S.Donmez A.Marchev D.Coggins-Hill S.A.,Mattingly A.Keel W.C.Haque S.Aungwerojwit A.Bergvall N.2025-08-11T20:18:33Z2010-03-08T12:34:43ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectspolarimetryinfrared-photometryvisible-astronomybroad-band-photometrysloan-photometryOJ287 is a BL Lac object at redshift z=0.306 that has shown double-peaked bursts at regular intervals of ~12yr during the last ~40yr. We analyse optical photopolarimetric monitoring data from 2005-2009, during which the latest double-peaked outburst occurred. The aim of this study is twofold: firstly, we aim to analyse variability patterns and statistical properties of the optical polarization light-curve. We find a strong preferred position angle in optical polarization. The preferred position angle can be explained by separating the jet emission into two components: an optical polarization core and chaotic jet emission. The optical polarization core is stable on time scales of years and can be explained as emission from an underlying quiescent jet component. The chaotic jet emission sometimes exhibits a circular movement in the Stokes plane. We find six such events, all on the timescales of 10-20days. We interpret these events as a shock front moving forwards and backwards in the jet, swiping through a helical magnetic field. Secondly, we use our data to assess different binary black hole models proposed to explain the regularly appearing double-peaked bursts in OJ287. We compose a list of requirements a model has to fulfil to explain the mysterious behaviour observed in OJ287. The list includes not only characteristics of the light-curve but also other properties of OJ287, such as the black hole mass and restrictions on accretion flow properties. We rate all existing models using this list and conclude that none of the models is able to explain all observations. We discuss possible new explanations and propose a new approach to understanding OJ287. We suggest that both the double-peaked bursts and the evolution of the optical polarization position angle could be explained as a sign of resonant accretion of magnetic field lines, a 'magnetic breathing' of the disc.2010MNRAS.402.2087Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/402/2087CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/129/569 : BVRI photometry of OJ 287 (Jia Guibin+ 1998)J/AJ/132/1256 : eim BATC photometry of OJ 287 (Wu+, 2006)J/MNRAS/385/823 : UBVRI light curves of OJ 287 (Zheng+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/402/2087https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/402/2087http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/402/2087https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/402/2087https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/402/2087http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/402/2087GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/MNRAS/402/2087/polarimPolarimetry of OJ 287recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Datedtime.epochdoubleTelTelescope used (1)instr.setupcharNNumber of points averagedmeta.numberintPQNormalized Stokes parameter P_Q_%phys.polarization.stokesfloate_PQrms uncertainty on PQ%stat.errorfloatPUNormalized Stokes parameter P_U_%phys.polarization.stokesfloate_PUrms uncertainty on PU%stat.errorfloatl_PolLimit flag on Polmeta.code.errorcharPolDegree of polarization%phys.polarizationfloate_Polrms uncertainty on Pol%stat.errorfloatPAPosition angle of the polarization vectordegpos.posAng;phys.polarizationfloate_PArms uncertainty on PAdegstat.errorfloatJ/MNRAS/402/2087/photomCombined table from original tablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Datedtime.epochdoubleBand[BVRIri] Filterinstr.bandpasscharmagApparent magnitude (1)magphot.magfloate_magMagnitude errormagstat.error;phot.magfloatTelTelescope used (2)instr.setupchar