TITLE: GCN CIRCULAR NUMBER: 16657 SUBJECT: GRB 140801A: Redshift from the 10.4m GTC telescope DATE: 14/08/02 04:56:21 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (IAA-CSIC, UPV/EHU), C.C. Thoene (IAA-CSIC), J.P.U. Fynbo (DARK/NBI), D. Xu (DARK/NBI), D. Perez-Valladares (GTC), and G. Gomez-Velarde (ULL-IAC, GTC) report on behalf of a larger collaboration: We have observed the afterglow of the Fermi GRB140801A (Gorbovskoy et al. GCN 16653, Xu et al. GCN 16655) with the 10.4m GTC (+OSIRIS). Spectroscopic observations began at 3:35 UT (8.59 hr after the burst). The first 900 s spectrum was obtained with the R1000B grism, and covered the range between 3630 and 7500 A, at a resolution of ~1000. We detect a strong continuum with absorption features that correspond to NiII, MnII, FeII, MgII, and MgI at a common redshift of z=1.320, which we identify as the redshift of the GRB. Further spectroscopic observations are ongoing.