GCN Circular 32670
Subject
GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
Event
Date
2022-10-10T22:04:05Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Kim (FAI), M. Krugov (FAI), A. Pozanenko (IKI), Y. Aimuratov (FAI),
S. Belkin (IKI, HSE), N. Pankov (HSE) report on behalf of GRB IKI FuN:
We observed GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632;
Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et
al., GCN 32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657;
Pillera et al., GCN 32658; Gotz et al., GCN 32660; Frederiks et al.,
GCN 32668) with AZT-20 telescope of Assy-Turgen observatory starting on
2022-10-10 (UT) 17:12:51. The observations were carried out sequentially
with three images for 30 seconds, in each filter. In stacked images we
clearly detect the optical afterglow (e.g. Dichiara et al., GCN 32632;
Lipunov et al., GCN 32634; Perley GCN 32638; Hu et al., GCN 32644;
Belkin et al., GCN 32645; Kuin et al., GCN 32656). Preliminary
photometry of the afterglow is following
Date UT start t-T0 Exp. Filter OT Err. UL(3sigma)
(mid, days) (s)
2022-10-10 17:12:51 n/a 18*30 r' 18.64 0.03 20.8
2022-10-10 17:14:51 n/a 15*30 g' 20.53 0.11 21.1
2022-10-10 17:21:07 n/a 15*30 i' 17.58 0.01 20.7
2022-10-10 17:24:16 n/a 15*30 z' 16.87 0.05 19.8
The photometry is based on the nearby PS1 stars.