[vsnet-grb-info 11336] GRB 111228A: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12748
SUBJECT: GRB 111228A: optical observations
DATE:    11/12/29 01:07:55 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani at dark-cosmology.dk>

V. Nascimbeni (Univ. Padova), E. Palazzi (INAF-IASFBo), D. Fugazza, A. 
Melandri, S. Covino (INAF-OABr), L. Borsato, A. Cunial, V. Granata 
(Univ. Padova), report on behalf of a larger collaboration:

We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with 
the 1.82m Asiago Telescope equipped with the AFOSC optical camera. A 900 
s R-band image was acquired with mean time Dec 28.939 UT (6.79 hr after 
the burst trigger).

We clearly detect the afterglow (Ukwatta et al., GCN 12737; Xin et al., 
GCN 12738; Klotz et al., GCN 12472) at a magnitude R = 18.6 +/- 0.02 
assuming R = 17.28 for the star USNO-B1 1083-0199833 (RA = 10:00:22.72, 
Dec = +18:19:23.85 - same as used by Klotz et al., GCN 12746).

We also clearly detect the SDSS object reported by Guver (GCN 12741), 
and confirm that it is not related to the GRB (Klotz et al., GCN 12746). 
Further observations are underway.