GCN Circular 23124
Subject
GRB 180809B: CrAO optical observations
Date
2018-08-10T19:50:36Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), V. Rumyantsev (CrAO), A. Pozanenko (IKI), A.
Volnova (IKI), report on behalf of larger GRB follow-up collaboration:
We observed the field of the GRB 180809B (Moss et al., GCN 23105)
with ZTSH 2.6m telescope of CrAO observatory starting on Aug. 9 (UT)
21:14:58. We took several images in BVRI filters with exposures of 120
s. We detect the afterglow (e.g., Moss et al., GCN 23105; Lipunov et
al., GCN 23109; Schweyer et al. GCN 23111; Guidorzi et al., GCN 23112,
Tiurina et al., GCN 23113).
Preliminary photometry of the afterglow in R- filter is following
UT start t-T0 Filter Exp. OT err
(mid, days) (s)
21:14:58.579 0.03276 R 1*120 19.80 0.05
21:17:05.489 0.03423 R 1*120 19.86 0.04
21:19:12.801 0.03570 R 1*120 19.93 0.05
21:25:54.597 0.04035 R 1*120 20.35 0.05
21:34:27.347 0.04629 R 1*120 20.86 0.08
21:43:00.178 0.05519 R 2*120 21.51 0.11
The photometry is based on nearby USNO-B1.0 stars:
Ref.stars
USNO-B1.0_id R2
0747-0765959 19.65
0746-0776364 18.76
0746-0776499 19.18