[vsnet-grb-info 13925] GRB 130912A: AAO optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15239
SUBJECT: GRB 130912A:  AAO optical upper limit
DATE:    13/09/21 16:53:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (IKI), R. Inasaridze (AAO), O. Kvaratskhelia (AAO), V. 
Ayvazian(AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 130912A (D'Elia et al., GCN 15212)
with AS-32 (0.7m) telescope of Abastumani Observatory starting  Sep., 13 
(UT) 00:18:46. We obtained several unfiltered frames with exposures of 
120 s. On stacked images within the enhanced XRT circle (Beardmore et 
al., GCN 15217) we did not detect an optical counterpart reported by 
Tanga et al. (GCN 15214).

The details of the photometry are the following:

t_start, UT   filter exptime,s   t-t0, mid, days  OT    uplim

21:39:21      None   31*120       0.68394         n/d    22.3

The photometry is based 3 USNO-B1.0 stars:

USNO-B1.0 id RA             Dec             R2
1040-0030312 03:10:30.46 +14:01:11.1 19.44
1040-0030310 03:10:29.14 +14:01:21.6 17.38
1040-0030302 03:10:25.12 +14:00:31.6 15.90