[vsnet-grb-info 26550] GRB 201014A: Redshift from GTC/OSIRIS

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28650
SUBJECT: GRB 201014A: Redshift from GTC/OSIRIS
DATE:    20/10/16 11:04:06 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte at iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D.A. Kann, M. Blazek, J.F. Agui Fernandez, C. Thoene (all HETH/IAA-CSIC), G. Gomez Velarde and A. Perez Romero (both GRANTECAN) report:

We observed the afterglow of GRB 201014A (Ambrosi et al. GCN 28623; D’Elia et al. GCN 28626; Pozanenko et al. GCN 28628) with the 10.4m GTC telescope, at Roque de los Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The observation started on 16 October 2020 at 5:10 UT (30.36 hrs after the GRB onset) and consisted of 3x1200s with the R1000B grism, covering the range between 3700 and 7800 Å. 

The spectrum shows signal redwards of 5150 AA, consistent with the Lyman forest, Lyman alpha, SiII, SiIV, OI, and CII at a common redshift of 4.56, which we identify as the redshift of the GRB.