[vsnet-grb-info 12243] GRB 120811C: Redshift from OSIRIS/GTC

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13628
SUBJECT: GRB 120811C: Redshift from OSIRIS/GTC 
DATE:    12/08/11 23:14:09 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte at iaa.es>

C. C. Thoene (IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC, DARK), 
J. Gorosabel, R. Sanchez-Ramirez (IAA-CSIC) and 
J. P. U. Fynbo (DARK) G. Gomez Velarde (GTC) report 
on behalf of a larger collaboration:

We observed the afterglow of GRB 120811C (Barlow et al., 
GCN 13622) with OSIRIS at the 10.4m GTC telescope starting at 
UT 22:07 (6.5 hr after the burst) for a total exposure time of 2400s. 
We used grism 1000B covering the wavelength range between 
3700 and 7800 Angstrom. 

Despite Calima, the continuum is clearly detected and the 
spectrum shows strong Ly alpha and Ly beta absorption as well 
as a number of absorption lines (SII, SiII, OI, CII, CIV, SiIV, AlII, 
AlIII, NiII, ZnII and SiII*) at a common redshift of z=2.671.