J/ApJ/835/275ivo://CDS.VizieR/J/ApJ/835/275doi:10.26093/cds/vizier.18350275CDSRakshit S.Stalin C.S.Muneer S.Neha S.Paliya V.S.2017-11-03T14:07:41Z2017-10-04T07:47:32ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomyphotometrypolarimetrybl-lacertae-objectsThe gamma-ray blazar OJ 287 was in a high activity state during 2015 December-2016 February. Coinciding with this high brightness state, we observed this source for photometry on 40 nights in R-band and for polarimetry on nine epochs in UBV RI bands. During the period of our observations, the source brightness varied from 13.20+/-0.04 mag to 14.98+/-0.04mag and the degree of polarization (P) fluctuated between 6.0%+/-0.3% and 28.3%+/-0.8% in R-band. Focusing on intranight optical variability (INOV), we find a duty cycle of about 71% using {chi}^2^-statistics, similar to that known for blazars. From INOV data, the shortest variability timescale is estimated to be 142+/-38min, yielding a lower limit of the observed Doppler factor {delta}_0_=1.17, the magnetic field strength B<=3.8G, and the size of the emitting region R_s_<2.28x10^14^cm. On internight timescales, a significant anticorrelation between R-band flux and P is found. The observed P at U-band is generally larger than that observed at longer-wavelength bands, suggesting a wavelength-dependent polarization. Using V-band photometric and polarimetric data from Steward Observatory obtained during our monitoring period, we find a varied correlation between P and V-band brightness. While an anticorrelation is sometimes seen between P and V-band magnitude, no correlation is seen at other times, thereby suggesting the presence of more than one short-lived shock component in the jet of OJ 287.2017ApJ...835..275Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/835/275CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/95/1 : Atlas of Quasar Energy Distributions (Elvis+ 1994)J/A+AS/116/403 : VRI photom. of stars in 12 BL Lac objects (Fiorucci+, 1996)J/A+AS/129/569 : BVRI photometry of OJ 287 (Jia Guibin+ 1998)J/A+AS/132/83 : BVRI photometry of 7 BL Lac objects (Bai+ 1998)J/A+AS/136/455 : BVRI photometry of 3 BL Lac objects (Bai+, 1999)J/ApJ/522/846 : Optical monitoring of GeV loud blazars (Xie+, 1999)J/A+A/385/55 : Long-Term Polarization of BL Lac (Hagen-Thorn+ 2002)J/A+A/450/39 : BVRI photometry of 8 red blazars (Gu+, 2006)J/AJ/132/1256 : eim BATC photometry of OJ 287 (Wu+, 2006)J/AJ/134/799 : Multiwaveband polarimetry of 15 AGN (Jorstad+, 2007)J/ApJ/672/40 : AO 0235+164 outburst in 2006 December (Hagen-Thorn+, 2008)J/MNRAS/385/823 : UBVRI light curves of OJ 287 (Zheng+, 2008)J/MNRAS/402/2087 : Opt. polarization of OJ 287 in 2005-2009 (Villforth+, 2010)J/AJ/141/65 : BATC ceimo light curves of OJ 287 (Dai+, 2011)J/MNRAS/421/1861 : OJ287 polarization and VLBI jet direction (Valtonen+, 2012)J/ApJ/747/63 : 7mm VLBA observations of BL Lac object OJ287 (Agudo+, 2012)J/ApJ/764/5 : Photom. of 2012 precursor flare in OJ287 (Pihajoki+, 2013)J/A+A/559/A20 : Historical outbursts of OJ287 (Hudec+, 2013)J/ApJ/789/135 : Gamma-ray bright blazars spectrophotom. (Williamson+, 2014)J/A+A/588/A45 : R-band polarisation of stars toward Gal 110-13 (Neha+, 2016)J/A+A/597/A80 : GMVA 86GHz images of OJ 287 (Hodgson+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/835/275https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/835/275http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/835/275https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/835/275https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/835/275http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/835/275GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfraredOpticaldefaultJ/ApJ/835/275/fig2Long term variation of R-band magnituderecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observationdtime.epochdoubleRmag[13.2/15] Apparent R band magnitudemagphot.mag;em.opt.Rfloate_Rmag[0.04/0.05] Error in Rmagmagstat.error;phot.mag;em.opt.RfloatJ/ApJ/835/275/table1Log of photometric observationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of the observationtime.epoch;obsnullableN[2/30] Number of data points in differential light curve (DLC)meta.numberintExp[300/1800] Exposure timestime.duration;obs.exposureintDur[0.2/4] Duration of monitoringhtime.durationfloatJ/ApJ/835/275/table2Results of polarization observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of observationtime.epoch;obsnullableBandObserving band (UBV RI R') (1)instr.bandpasscharJDJulian date of the observationdtime.epochdoublePol[6/38.7] Degree of polarization%phys.polarizationfloate_Pol[0.2/3] Pol uncertainty%stat.errorfloatPA[58.6/130.6] Polarization position angledegpos.posAngfloate_PA[0.3/3.1] PA uncertaintydegstat.errorfloat