Fast optical brightening of BL Lacertae
ATel #3371; V. M. Larionov, E. G.Larionova and N. V.Efimova (Astronomical Institute, St.-Petersburg State University, Russia, and Pulkovo Observatory, Russia), M. Villata and C. M. Raiteri (INAF, Osservatorio Astronomico di Torino, Italy), for the GASP Collaboration
on 23 May 2011; 08:50 UT
Credential Certification: Claudia M. Raiteri (email@example.com)
Subjects: Optical, AGN, Blazar
With reference to ATel #3368, announcing the Fermi LAT detection of increasing gamma-ray activity of BL Lacertae, we report on its optical brightening.
Observations in St. Petersburg reveal R = 13.87 +/- 0.01 on May 14.99, R = 13.06 +/- 0.01 on May 21.95 and R = 12.71 +/- 0.01 on May 22.97, with a brightness increase of 0.36 mag in 24.5 hours.
These brightness levels are comparable to those reached during the outbursts of 1997-2004.