GCN Circular 22346
Subject
GRB 180115A: Redshift from OSIRIS/GTC
Date
2018-01-15T22:57:40Z (6 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo,
C.C. Thoene, D.A. Kann (HETH/IAA-CSIC), N. Castro-Rodriguez
(Grantecan, IAC, ULL), D. Perez Valladares (Grantecan) report on
behalf of a larger collaboration:
We observed the afterglow of GRB 180115A (Cannizzo et al. GCN 22335,
Cano et al. GCN 22345) with OSIRIS at the 10.4m GTC telescope. The
observation consisted of 3x900s exposure with grism R1000B, covering
the range between 3700 and 7800 Angstrom and was performed under
bad seeing conditions.
The observation started at 20:32 UT (16.28 hr after the burst), and the
acquisition image shows the afterglow at r=21.2+/-0.2. The spectrum
shows a weak continuum over all the spectral range. The low signal to
noise ratio of the spectrum only allows us to detect a single broad spectral
feature that we identify as Lyman alpha at a redshift of 2.487.