GCN Circular 29320

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

We obtained spectroscopy of the host galaxy of GRB 200613A (Fermi-LAT 
detection: Ohno et al. GCN #27931; Fermi GBM detection: Bissaldi & Lesage, 
GCN #27930; optical counterpart discovery: Kann et al. GCN #27935) with OSIRIS, 
mounted on the 10.4m GTC telescope (Roque de los Muchachos Observatory, 
La Palma, Spain). The observation was performed on the 18 January 2021 with 
mean epoch at 00:02 UT (218.75 days after the burst) and consisted of 3x1200s 
exposures with grism R1000R, covering the range between 5100 and 10100 ��. 

The spectrum is characterised by a continuum that is detected over the complete 
spectral range, with better SNR in the blue part of the spectrum, and has a strong 
emission feature that we identify as the [OII] 3727/3729 doublet, at a redshift of 
1.2280. At a similar redshift of 1.2255 we also identify absorptions due to FeII and 
MgII, that allow us to confirm the redshift, which we identify as that of GRB 200613A.