Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 17198

GRB 141220A: Redshift from OSIRIS at the 10.4m GTC
2014-12-20T07:53:28Z (9 years ago)
Antonio de Ugarte Postigo at IAA-CSIC <>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
J. Gorosabel (UPV, IAA-CSIC), N. Tanvir (U. Leicester), J.P.U. Fynbo (DARK/NBI),
P. Pesev (GRANTECAN), G. Gomez Velarde (GRANTECAN), and 
D. Perez Valladares (GRANTECAN) report on behalf of a larger collaboration

We observed the afterglow of GRB141220A (Cummings et al. GCN 17196, Gorosabel
et al. GCN 17197) with OSIRIS at the 10.4m GTC. Observations began at 6:45 UT 
(50 min after the burst). In a first 600 s spectrum obtained with grism R1000B covering 
from 3750 to 7800 A we detect absorption features of AlII, FeII, MgII, MgI, at a redshift 
of 1.3195, including several absorptions of FeII* which make it very likely the redshift of 
the GRB. We also detect two MgII intervening systems at redshifts of 1.280 and 0.527.
Looking for U.S. government information and services? Visit