The blazar BL Lacertae is brightening in Optical bands
ATel #16856; Shubham Kishore, Alok C. Gupta (Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263001, India)
on 9 Oct 2024; 09:29 UT
Credential Certification: Dr. Alok C. Gupta (acgupta30@gmail.com)
Subjects: Optical, Blazar
Referred to by ATel #: 16865
In the follow-up of the blazar BL Lacerate, which was recently detected in very high-energy gamma-rays by Fermi-LAT, LHAASO, and VERITAS (ATels #16849, #16850, #16854), and in X-rays, UV, and optical bands (ATel #16855). We performed optical BVRI photometric monitoring of the blazar on October 4, 2024, using a 1.3-meter Devasthal Fast Optical Telescope (DFOT) located at Aryabhatta Research Institute of Observational Sciences (ARIES), Devasthal, Nainital, India. The telescope is equipped with a CCD detector and BVRI broad-band optical filters. On October 4, 2024 we detected the source at following magnitudues in different optical bands: B = 14.194 +-0.005 mag (JD = 2460588.0522106), V = 13.124+-0.002 mag (JD = Â 2460588.0496296), R = 12.615+-0.002 mag (JD = 2460588.0475926), and I = 11.900 +-0.002 mag (JD = 2460588.0458565). The observations reported here show the blazar is still about 1.4 mag fainter than its historical brightest state detected in mid-2021 (Raiteri et al. 2023, MNRAS, 522, 102). The current high activity state in optical bands of this blazar deserves close monitoring in optical bands as well as in multi-wavelengths.
