GCN Circular 32645
Subject
GRB 221009A (Swift J1913.1+1946): Mondy optical observations
Date
2022-10-10T08:10:47Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI, HSE), A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov
(HSE) report on behalf of GRB IKI FuN:
We observed GRB 221009A (Swift J1913.1+1946) (Swift-BAT detection of
Swift J1913.1+1946: Dichiara et al., GCN 32632; Kennea and Williams, GCN
32635; Fermi-GBM detection: Veres et al., GCN 32636; Fermi-LAT
detection: Bissaldi et al., GCN 32636, IPN localization: Svinkin et
al., GCN 32641) with AZT-33IK telescope of Sayan observatory (Mondy)
starting on 2022-10-09 (UT) 14:26:54 and continuing to 15:34:05.
We clearly detect the optical afterglow (Dichiara et al., GCN 32632;
Lipunov et al., GCN 32634; Perley GCN 32638; Hu et al., GCN 32644).
Preliminary photometry of the afterglow at the first image is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-10-09 14:26:54 0.01223 R 120 14.84 0.09 20.8
We observe a monotonic decay in brightness, which can be approximated by
a power law with an index of -0.52.
The photometry is based on the nearby USNO-B1.0 stars (R2)