GCN Circular 29577
Subject
GRB 210217A: Mondy optical observations
Event
Date
2021-02-26T18:35:21Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N.Pankov (HSE), S. Belkin (IKI), A. Pozanenko (IKI), E. Klunko (ISTP)
report on behalf of IKI GRB FuN:
We observed the field of GRB 210217A (Simpson et al., GCN 29521) with
AZT-33IK telescope of Sayan observatory (Mondy) on 2021-02-19 and XX.
Within enhanced XRT position (Evans et al., GCN 29525) we do not detect
afterglow (Simpson et al., GCNs 29521,29555; Zhu et al., GCN 29523;
Zheng et al., GCN 29533; Shrestha et al., GCN 29535; Kumar et al., GCN
29539). Preliminary photometry of the filed is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-02-19 13:10:59 1.58579 R 2190 n/d n/d 22.2
2021-02-21 16:05:26 3.71250 R 3150 n/d n/d 22.8
2021-02-19+2021-02-21 2.65193 R 5850 n/d n/d 22.9
The photometry is based on the nearby USNO-B1.0 star
USNO-B1.0_id R2
1587-088041 17.94
A light curve of afterglow of GRB 210217A (based on published
photometry) and upper limits can be found in
http://grb.rssi.ru/GRB210217A/GRB210217A_LC.jpg
Using upper upper limit we may suggest a possible jet break of the
light curve we may suggest a jet break between 1.58 and 3.71 days after
power law decay with index alpha of -0.48 (Shrestha et al., GCN 29535).