GCN Circular 32889
Subject
GRB 221028A: CrAO/ZTSh optical upper limit
Event
Date
2022-10-29T20:04:27Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), N. Pankov (HSE), V. Rumyantsev (CrAO), A. Pozanenko
(IKI) report on behalf of IKI GRB FuN:
We observed the GRB 221028A (Lien et al., GCN 32874; Ursi et al., GCN
32885) with ZTSh 2.6m telescope of CrAO observatory starting on Oct. 28
(UT) 19:38:37. We do not detect any optical object within XRT
localization (Lien et al., GCN 32874). This is consistent with reported
non-detections (Hu et al., GCN 32878; Kumar et al., GCN 32876;
Lipunov et al., GCN 32879; Strausbaugh et al., GCN 32881; Niwano et al.,
GCN 32883; Kumar et al., GCN 32886; Watson et al., GCN 32888).
Preliminary photometry of the field in a combined image is following
Date UT start t-T0 Filter Exp. OT err UL(3sigma)
(mid, days) (s)
2022-10-28 19:38:37 0.27233 R 10*120 n/d n/d 20.7
The photometry is based on several nearby USNO-B1.0 (R2) stars
USNO-B1.0
RA DEC R2
20:56:40.7621 +41:04:57.000 15.60
20:56:51.9768 +41:04:22.922 17.21
20:57:00.0629 +41:02:55.072 16.04