High Optical Activity of Several Gamma-Ray Blazars

Astronomer's Telegram #4122 ;

Svetlana Jorstad (Boston Univ., USA and St. Petersburg Univ. Russia),Valeri Larionov, and Evgenia Kopatskaya (St. Petersburg Univ., Russia)
on 23 May 2012; 08:45 UT

According to our optical observations at the 1.8 m Perkins telescope of Lowell observatory (Flagstaff, AZ) and at the 70-cm AZT-8 (CrAO, Ukraine) the quasar B2 1156+295 (4C +29.45 = Ton 599) has entered a new phase of a high optical activity. The source had an optical flare along with a moderate increase of the gamma-ray activity in the end of April 2012 (Atel #4051) when the quasar reached R~15.1 and then faded up to R~16. Our recent observations show that on May 19 the source was R=15.99+-0.02 while tonight, on May 23, its brightness reached R=14.774+-0.007. The source appears to continue to brighten. The optical polarization is very variable. Three other gamma-ray blazars, 1749+096 (OT +081), 1222+216 (4C +21.35), and 3C279, show an interesting optical activity as well. The brightness of the BLLac object 1749+096 increased by ~1mag and for the quasars, 1222+216 and 3C279, by ~0.5mag with respect to their brightness in R band in the end of April. The multifrequency observations are encouraged.