TITLE:   GCN CIRCULAR
NUMBER:  17234
SUBJECT: GRB 141225A: Redshift from OSIRIS at the 10.4m GTC
DATE:    14/12/26 03:08:38 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (UPV-EHU, IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC,
DARK/NBI), C.C. Thoene (IAA-CSIC),  N. Tanvir (U. Leicester), J.P.U. Fynbo
(DARK/NBI), D. García-Alvare (GTC), "A. Perez-Romero (GTC)
report on behalf of a larger collaboration:

We observed the afterglow of GRB 141225A (D'Avanzo et al. GCN 17229) with
OSIRIS at the 10.4m GTC. Observations began at 00:25:25 UT (~1.4 hours
post burst). Four 600s spectra were taken with the R1000B grism going from
3750 to 7800 AA. A first analisys based on archival arc lamps reveals
absorption features of FeII and MgII at a preliminary redshift of z=0.915.

[GCN OPS NOTE(27dec14): Pera author's request, D.G was changed to D.G-A
and A.P-R was added.]