J/AJ/148/110ivo://CDS.VizieR/J/AJ/148/110doi:10.26093/cds/vizier.51480110CDSMan Z.Zhang X.Wu J.Zhou X.Yuan Q.2017-06-26T11:50:48Z2014-12-09T17:13:51ZCDS support team

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

cds-question@unistra.frbl-lacertae-objectsgalaxiesphotometryWe present the results of the first systematic long-term multicolor optical monitoring of the BL Lacertae object 1ES 0806+52.4. The monitoring was performed in multiple passbands with a 60/90cm Schmidt telescope from 2005 December to 2011 February. The overall brightness of this object decreased from 2005 December to 2008 December but was regained after that. A sharp outburst probably occurred around the end of our monitoring program. Overlapping the long-term trend are some short-term small-amplitude oscillations. No intranight variability was found in the object, which is in accordance with the historical observations before 2005. By investigating the color behavior, we found a strong bluer-when-brighter chromatism for the long-term variability of 1ES 0806+52.4. The total amplitudes at the c, i, and o bands are 1.18, 1.12, and 1.02mag, respectively. The amplitudes tend to increase toward shorter wavelengths, which may be a major cause of the bluer-when-brighter chromatism. Such bluer-when-brighter chromatisms are also found in other blazars, such as S5 0716+714, OJ 287. The hard-X-ray data collected from the Swift/BAT archive was correlated with our optical data. No positive result was found, the reason for which may be that the hard-X-ray flux is a combination of the synchrotron and inverse Compton emission, but with different timescales and cadences under the leptonic synchrotron self-Compton model.2014AJ....148..110Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/148/110CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/262 : BATC Data Release One - BATC DR1 (Zhou+ 1995-2005)J/AJ/143/108 : B'V'R' photometry of the BL Lac object S5 0716+714 (Wu+, 2012)J/AJ/141/65 : BATC ceimo light curves of OJ 287 (Dai+, 2011)J/AJ/132/1256 : eim BATC photometry of OJ 287 (Wu+, 2006)J/AJ/129/1818 : Photometry of S5 0716+714 (Wu+, 2005)J/A+A/397/361 : 15-color BATC photometry of Landolt SA95 field (Zhou+, 2003)J/AJ/117/2757 : Surface photometry of NGC 5907 (Zheng+, 1999)J/AJ/112/628 : BATC Color Survey of M67 (Fan+ 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/148/110https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/148/110http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/148/110https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/148/110https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/148/110http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/148/110GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/148/110/photometryObservational log and results in the c, e, i, m, and o bandsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsUT date of the observationstime.epoch;obsnullableJDJulian Date of the observationdtime.epochdoubleExpExposure timestime.duration;obs.exposureintBandMagnitude band (c, e, i, m, or o)instr.bandpasscharmagThe magnitude (1)magphot.magfloate_magError in magmagstat.error;phot.magfloatDmagDifferential magnitude (2)magphot.mag;arith.difffloat