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

GCN Circular 17564

GRB 150309A: ISON-Kislovodsk optic upper limit
2015-03-11T12:35:27Z (9 years ago)
Alexei Pozanenko at IKI, Moscow <>
E. Vazaeva (IKI), V. Nevskiy (ISON), A. Volnova (IKI), I. Molotov 
(KIAM), A. Pozanenko (IKI),report on  behalf of larger collaboration:

We observed the field of the Swift GRB 150309A (Cummings et al., GCN 
17553) with Santel-400AN   telescope of ISON-Kislovodsk observatory 
starting on Mar. 09 (UT) 23:11:26, i.e. ~8.5 min after the burst 
trigger. In the enhanced XRT position (Osborne et al., GCN 17555) we do 
not detect any object. An upper limit is following

Date       UT start   t-T0    Filter   Exp.     UL(3 sigma)
                      (mid, days)        (s)

2014-09-03 23:11:26  0.02590  None     49*60    20.0

The photometry is based on USNO-B1.0 star

USNO-B1.0_id  R2

1764-0030460  15.42
Looking for U.S. government information and services? Visit