TITLE: GCN CIRCULAR NUMBER: 29320 SUBJECT: GRB 200613A: Host galaxy redshift from OSIRIS/GTC DATE: 21/01/18 17:29:38 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC 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 Å. 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.