GCN Circular 18197
Subject
GRB 150821A: LCOGT Sutherland observations
Date
2015-08-23T11:56:57Z (9 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana),
C. Mundell (U. Bath) on behalf of a larger collaboration report:
The 1-m LCOGT telescopes in Sutherland (South Africa) began observing
Swift GRB 150821A (Troja et al. GCN 18186) on August 21, 19:39 UT (~9.9
hours after the burst trigger) with SDSS r and i filters.
At the position of the optical afterglow (Troja et al. GCN 18186; D'Elia
et al. GCN 18187; Kuin et al. GCN 18192; Kruehler et al. GCN 18195) we
do not detect any source down to the following limits:
Mid Time Exposure Filter Magnitude
(hrs) (s)
---------------------------------------------------
10.4 2880 r' > 20.4
10.6 2880 i' > 21.0
---------------------------------------------------
Calibration is done against R2 and I values of USNOB-1 nearby stars.