GCN Circular 29894
Subject
GRB 210420B: Zeiss-1000 of Koshka optical observations
Event
Date
2021-04-23T18:31:49Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE, IKI), S. Naroenkov (INASAN), A. Pozanenko (IKI), S.
Belkin (IKI), M. Ibrahimov (INASAN) report on behalf of IKI GRB FuN:
We observed the field of GRB 210420B (Moss et al., GCN 29833; Lien et
al., GCN 29854; Osborne et al. GCN 29876; Stamatikos et al., GCN29879)
with Zeiss-1000 telescope of Koshka observatory (INASAN). We marginally
detect the optical afterglow (Lipunov et al., GCN 29845; Oksanen et
al., GCN 29846; Hu et al., GCN 29847; Tianrui Sun et al., GCN 29848;
Leonini et al., GCN 29851; de Ugarte Postigo et al., GCN 29852, 29853;
Watson et al., GCN 29858; Zheng et al., GCN 29861; Breeveld et al., GCN
29862; Stecklum et al., GCN 29863; Butler et al.,GCN 29864; Jelinek et
al., GCN 29866; Watson, GCN 29867; Leonini et al., GCN 29872; Guelbenzu
et al., GCN 29890).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-04-21 20:02:55 15*180 1.03507 R 21.0 0.3 21.0
2021-04-22 20:16:45 24*180 2.05405 R n/d n/d 20.5
The photometry is based on the nearby USNO-B1.0 stars
USNO_B1.0_id R2
1325-0345119 16.12
1326-0349499 16.57