GCN Circular 31431
Subject
GRB 220107A: SAO RAS optical observations
Date
2022-01-11T05:08:48Z (2 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO), on behalf of larger GRB follow-up team report:
We observed the field of GRB 220107A (The Fermi GBM team, GCN 31399;
Kunzweiler et al. GCN 31400; DeLaunay et al. GCN 31402; Suresh et al.,
GCN 31408; Ridnaia et al., GCN 31429) with the SAO RAS 1-m telescope
Zeiss-1000 + CCD-photometer. Two series of images in Rc band
were obtained: the 1st under moderate weather conditions
and the 2nd with relatively clear sky.
The OT (Hosokawa et al. GCN 31413; Siegel GCN 31415; Zhu et al.
GCN 31416; Pankov et al., GCN 31419; Moskvitin et al., GCN 31422;
Castro-Tirado et al., GCN 31423, Moskvitin & Medvedev, GCN 31426)
is clearly visible in the stacked frames. Preliminary photometry
of the afterglow is as follows (based on nearby SDSS-DR12 stars
mentioned in GCNs 31422, 31426).
UT start -- UT end T_mid-T0, d Exp., s R_mag +/- err series
Jan. 10 Jan. 11
23:22:13 -- 02:06:39 3.41592 23 x 300 21.69 +/- 0.10 1st
Jan. 11 Jan. 11
02:49:39 -- 03:30:10 3.51694 8 x 300 22.03 +/- 0.09 2nd