The FSRQ B2 1308+326: the new activity phase around gamma-ray flare in January
ATel #16972; V. V. Vlasyuk, O. I. Spiridonova, A. S. Moskvitin (Special Astrophysical Observatory of the Rus. Ac. Sci.)
on 10 Jan 2025; 19:49 UT
Credential Certification: Alexander Moskvitin (mosk@sao.ru)
Subjects: Optical, Blazar, Quasar
Referred to by ATel #: 16977
The flat spectrum radio quasar B2 1308+326 is undergoing extended activity phase in optical range after two powerful flares in gamma-rays in December and January, as it was reported by Fermi LAT Collaboration (ATel #16940, #16970). The daily averaged gamma-ray flux (E > 100MeV) of the last flare was equal to (2.7 +/- 0.2) X 10^-6 photons cm^-2 s^-1 on January 6. This level exceeds the previous flare in last December by a factor of 2.
The behavior of the B2 1308+326 optical emission was reported 10 days ago (ATel #16963, #16964). We have inspected the optical brightness of FSRQ using 1 meter SAO RAS reflector, equipped by CCD photometer.
After some dimming of flux since epoch MJD = 60676 (R = 13.36) to MJD = 60678.09 (R = 13.98) the blazar begun new stage of re-brightening and reached R = 13.44 (MJD = 60684.03) and R = 13.56 (MJD = 60685.06) over last two nights. The following observations are in progress.
Typical accuracy of our data was about 0.01 mag. under good transparency and seeing value (FWHM) below 1".5. As before, for data calibration we used comparison star F, assuming its R = 14.00 mag. More accurate reduction is necessary. We strongly encourage further multi-wavelength investigations.
