Optical follow-up observations of the flaring blazar BL Lacertae
ATel #14343; Alok C. Gupta, V. Dhiman, P. Kushwaha, S. Kishore, H. Gaur, T. Tripathi (Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital - 263001, India)
on 23 Jan 2021; 08:05 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Dr. Alok C. Gupta (acgupta30@gmail.com)
Subjects: Optical, Blazar
Since October 2020 to till date, we are observing the blazar BL Lacertae (RA: 22 02 43.29 Dec: +42 16 39.98 J2000.0) at redshift z = 0.069 in optical BVRI bands using 1.04m ST (Sumpurnanand Telescope) and 1.3m DFOT (Devasthal Fast Optical Telescope) of ARIES, Nainital, India. The observations are carried out for our independent projects as well as a part of WEBT (whole earth blazar telescope) collaboration. We have carried out observations in many nights as 1-2 sets in BVI bands and continuous monitoring in R band for a few hours which provided a few thousands of image frames of BL Lacertae.
As reported to be the brightest state of the source obtained by WEBT collaboration on 2021 January 17.87(UT) with R = 12.45 ATel #14328. Here we are reporting the randomly selected R band observations in October - December 2020, and January 15, 16, 20, 2021. The magnitude of BL Lacerate are reported as follows:
Civil Date (UT) Mag+-error
2020 Oct. 27(12:45) 12.953+-0.004, 2020 Nov. 27(12:33) 13.053+-0.002, 2020 Dec. 11(13:19) 12.522+-0.002, 2021 Jan. 15(13:01) 11.998+-0.002, 2021 Jan. 16(12:58) 11.954+-0.002, and 2021 Jan. 20(12:57) 12.006+-0.005
These measurements were obtained using the photometric standard stars made available by LSW, Heidelberg, Germany (https://www.lsw.uniheidelberg.de/projects/extragalactic/charts/2200+420.html).
Any inquiry on these observations can be addressed to Alok C. Gupta (acgupta30@gmail.com). We will continue our monitoring of the source in the following nights.
A brief description of the instrumental setup used at ARIES, India for the presented observations is given at the official webpage of the Institute (see link below).
https://www.aries.res.in/facilities/astronomical-telescopes
