TITLE:   GCN CIRCULAR
NUMBER:  12761
SUBJECT: GRB 111228A: Gemini South Redshift
DATE:    11/12/29 08:25:14 GMT
FROM:    Antonino Cucchiara at LBNL  <acucchiara@lbl.gov>

A. Cucchiara (UCSC/UCO Lick), A. J.  Levan (U. Warwick), 
and S. B. Cenko (UC Berkeley) report:

We obtained spectroscopy of the optical afterglow of 
GRB 111228A (Ukwatta et al., GCN 12737) using GMOS-South 
on the Gemini-South 8-m telescope.  
Observations began on December 29.28 UT (15 hrs after the 
BAT trigger). 

Inspection of the first two exposures (range 4160-8140 Angstroms) 
reveals MgII2796,2803, MgII2853 and CaH&K absorption features 
at a common redshift of 0.716.

We therefore suggest this to be the redshift of GRB 111228A.

We thank the Gemini staff for performing this observation, 
in particular Pascale Hibon.