Recent optical activity of Mrk 421
ATel #4982; E. Semkov, R. Bachev, A. Strigachev, S. Ibryamov, S. Peneva (Institute of Astronomy and NAO, Sofia, Bulgaria), A. C. Gupta (ARIES, Nainital, India)
on 16 Apr 2013; 12:08 UT
Credential Certification: E. Semkov (email@example.com)
Subjects: Optical, Blazar
Referred to by ATel #: 5021
Our BVRI optical observations of Mrk 421 were performed within the multiwavelength international campaign (December 2012-June 2013), with the participation of GASP-WEBT, Swift, MAGIC, VLBA, NuSTAR, Fermi, VERITAS, F-GAMMA and other collaborations. Following the reports of enhanced X-ray and gamma activity of Mrk 421 (ATel #4978, ATel #4977, ATel #4976, ATel #4974, ATel #4918), we observed this blazar with the optical telescopes of the National Astronomical Observatory Rozhen and the Astronomical Observatory Belogradchik, Bulgaria. Our preliminary results indicate enhanced optical emission as well. The measured R-band magnitudes (7.5 arcsec aperture) were 11.74 (April 09.94 UT), 11.71 (April 10.92), 11.83 (April 11.84) and 11.90 (April 12.83) with a typical measurement error of about 0.01. Our previous observations of this object between March 01 and March 17 show R-band magnitudes of 12.0-12.2.