[vsnet-grb-info 11665] GRB 120311A: C88 optical limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13058
SUBJECT: GRB 120311A: C88 optical limits
DATE:    12/03/13 12:45:03 GMT
FROM:    Simone Leonini at Monarrenti Obs  <s.leonini at iol.it>

Simone Leonini and Paolo Rosi (Montarrenti Observatory, Siena, Italy)
report:

We observed the field of GRB 120311A (Swift trigger 517469, Markwardt et al.,
GCN 13032) with 0.53m RC telescope + U47 detector at Montarrenti Observatory
(Siena, Italy, IAU code C88).

The observations were performed in four sessions (~22 hours after the
trigger):

from 2012-03-12 03:22:33 UT to 2012-03-12 03:23:15 UT
from 2012-03-12 04:16:03 UT to 2012-03-12 04:16:46 UT   
from 2012-03-12 04:18:09 UT to 2012-03-12 04:18:52 UT   
from 2012-03-12 04:20:16 UT to 2012-03-12 04:20:59 UT

Eight unfiltered images of 40s exposure were obtained.
We do not detect any new point source in the coadded images (limit R~19.1,
USNO-B1 catalogue) within the refined XRT error circle (Goad et al.,GCN Circ
13035) or in the afterglow candidate position reported by Melandri et al.
(GCN Circ 13033).  Observations were made on the twilight.