GCN Circular 29692
Subject
GRB 210321A: CrAO optical upper limit
Event
Date
2021-03-22T19:02:33Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), S. Nazarov (CrAO), A. Pozanenko (IKI), S. Belkin (IKI)
report on behalf of GRB IKI FuN:
We observed the field of GRB 210321A (Dichiara et al., GCN 29677) with
AZT-8 telescope of CrAO observatory starting on 2021-03-21 (UT)
19:04:11. The optical afterglow (Siegel et al., GCN 29679; Butler et
al., GCN 29680; Lipunov et al., GCN 29683; Heintz et al., GCN 29684;
de Ugarte Postigo et al., GCN 29685; Xin et al. GCN 29687; Pankov et
al., GCN 29689) is not detected in a combined image. Preliminary
photometry of the field is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-03-21 19:04:11 0.51238 R 55*60 n/d n/d 20.8
The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1601-0068003 15.84
1600-0068970 16.18
1601-0068018 16.54
1601-0067995 16.23