Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 12761

GRB 111228A: Gemini South Redshift
2011-12-29T08:25:14Z (13 years ago)
Antonino Cucchiara at LBNL <>
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.
Looking for U.S. government information and services? Visit