GCN Circular 30440
Subject
GRB 210704A: Assy optical afterglow upper limit
Date
2021-07-10T23:24:16Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE, IKI), S. Belkin (IKI), V. Kim (FAI, Pulkovo
Observatory), A. Pozanenko (IKI), M. Krugov (FAI) report on behalf of
GRB IKI FuN:
We observed GRB 210704A (Ursi et al., GCN 30372; Berretta et al., GCN
30375; Prasad et al., GCN 30378; D'Ai et al., GCN 30379; Malacaria et
al., GCN 30380; Ridnaia et al., GCN 30388) with AZT-20 telescope of
Assy-Turgen observatory starting on 2021-07-08 (UT) 16:59:54. We do not
detect the optical afterglow (Kim et al., GCN 30384; D'Avanzo et al.,
GCN 30385; Troja et al., GCN 30390; Kann et al., GCN 30391, 30401; Sun
et al., GCN 30411; D'Avanzo et al., GCN 30432; Rastinejad et al., GCN
30433; Watson et al., GCN 30436).
Preliminary photometry of the filed is following
Date UT start t-T0 Exp. Filter OT Err. UL(3sigma)
(mid, days) (s)
2021-07-08 16:59:54 3.92014 77*60 r' n/d n/d 23.1
The photometry is based on the nearby PS1 stars.
Our photometry is consistent with observations of (D'Avanzo et al., GCN
30432; Watson et al., GCN 30436).