Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

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.
Looking for U.S. government information and services? Visit USA.gov