GCN Circular 29438
Subject
GRB 210204A (ZTF21aagwbjr/AT2021buv): continued Mondy optical observations
Event
Date
2021-02-09T12:40:35Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov (HSE)
report on behalf of GRB IKI FuN:
We continued observation of the ZTF21aagwbjr/AT2021buv transient (Kool
et al., GCN 29405) at the redshift of 0.876 (Xu et al., GCN 29432) which
is an afterglow (Kennea et al., GCN 29413; Teja et al., GCN 29414) of
GRB 210204A (Fermi GBM team, GCN 29390; Li et al., GCN 29392; Hurley
et al., GCN 29408; Waratkar et al., GCN 29410; Frederiks et al., GCN
29415). Images in R-filter were taken in AZT-33IK telescope of Sayan
observatory (Mondy) on Feb.7 and Feb.8.
Preliminary photometry of the optical transient in combined images in
two epochs is following
Date UT start t-T0 Filter Exp. OT Err. UL(3s) Telescope
(mid, days) (s)
2021-02-07 13:43:58 3.32260 R 60*60 20.61 0.04 22.8 AZT-33IK
2021-02-08 15:22:01 4.39035 R 59*60 20.92 0.05 22.7 AZT-33IK
The photometry does not contradict a possible jet-break suggested by
Rossi et al (GCN 29433).
The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1014-0149033 15.43
1014-0149115 17.00