GCN Circular 18274
Subject
GRB 150910A: Redshift from 10.4m GTC+OSIRIS
Date
2015-09-11T00:17:10Z (9 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
Antonio de Ugarte Postigo (IAA-CSIC, DARK/NBI), Christina Thoene (IAA-CSIC),
Gianluca Lombardi (IAC, ULL, GRANTECAN), and Alberto Perez (GRANTECAN)
report on behalf of a larger collaboration:
We have observed the afterglow of GRB 150910A (Pagani et al., GCN 18264)
using the 10.4 m GTC telescope equipped with OSIRIS. Our observation began
at 23:11 UT (14.1 hr after the burst) and consisted of 3x900s exposures using the
R1000B grism. The spectrum covers the wavelength range between 3700 and
7800 AA.
The acquisition image shows the afterglow at a magnitude of r=20.65+/-0.07 as
compared to SDSS stars.
The first spectrum shows a continuum throughout the full spectral range, with
several absorption features that correspond to AlII, AlIII, FeII, MgII and MgI at a
common redshift of 1.360, which we interpret as the redshift of the GRB.