[ Previous | Next | ADS ]

Optical and gamma-ray brightening of blazar OC 457

ATel #4779; D. Blinov, (St. Petersburg Univ.), I. Myserlis, E. Angelakis (MPIfR), O. King (Caltech), V. Pavlidou (Univ. of Crete) for the RoboPol Collaboration
on 2 Feb 2013; 16:08 UT
Credential Certification: Oliver King (ogk@astro.caltech.edu)

Subjects: Optical, Gamma Ray, AGN, Black Hole, Blazar

The RoboPol Collaboration is currently performing a preliminary photopolarimetric survey of gamma-ray bright blazars in the frame of the RoboPol project. We report that blazar OC 457 (a.k.a. S4 0133+47) is now in a flaring state. Preliminary estimated R magnitude was 14.9 on 2013 Jan. 24.70 UT and R=15.0 on Jan. 26.77 UT, which is significantly brighter than previously reported R=19.25 (Healey et al., 2008). R-band polarization is also high PD=16.4+-0.6%. Analysis of publicly available data of the LAT onboard of the Fermi gamma-observatory also reveals a brightening at gamma-ray wavelengths. Weekly averaged gamma-ray flux reached 2.5E-7 ph cm^-2s^-1 (E>100MeV) on Jan. 24, about 6 times greater than the average flux reported in the second Fermi LAT catalog (2FGL). Multifrequency observations of the blazar are encouraged.