GCN Circular 9323
Subject
GRB 090423: optical limit
Date
2009-05-05T00:21:38Z (15 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev, E. Pavlenko, O. Antoniuk (CrAO), A. Pozanenko (IKI) report on
behalf of larger GRB follow-up collaboration:
We observed the error box of Swift GRB 090423 (Krimm et al. GCN 9198) on
Apr. 23 between (UT) 090423 23:34:46 -- 090424 01:13:20 in R -filter with
Shajn telescope of CrAO. The observation was planning and performed before
the redshift z ~ 8 of GRB 090423 was confirmed (Cucchiara et al. GCN 9213;
Olivares et al. GCN 9215; Thoene et al. GCN 9216; Tanvir et al. GCN
9219). Indeed we do not detect optical afterglow at the place of IR
afterglow detection (Tanvir et al. GCN 9202; Levan et al. GCN 9206;
Cucchiara et al. GCN 9209). Limiting magnitude of the combined image is
following :
T0+ Filter, Exposure, mag., err.
(d) (s)
0.6877 R 93x60 >24.0 (3 sigma)
The combined R-image can be found at
http://grb.rssi.ru/GRB090423/GRB090423_ZTSh_a.gif