GCN Circular 13441
N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick), D. Fox (Penn State), A. Fruchter (STScI) and D. Krogsrud (Gemini) report on behalf of a larger collaboration: We observed the afterglow of GRB 120711A (Gotz et al. GCN 12434; Lacluyze et al. GCN 12430) using the GMOS-S spectrograph on Gemini-South. Observations began at 2012-7-11 10:08 UT, about 7.5 hr post-burst. The data were obtained at high air-mass and on the boundary of twilight, so the signal-to-noise is rather poor. Nevertheless, in the spectrum we identify lines of MgII (2797/2804A) and FeII (2374/2383/2587/2600A) at a common redshift of z=1.405. This therefore provides a robust lower-limit to the redshift of the GRB. Furthermore, given the lack of other absorption features, in particular any matching a redshift z~3 (Elliott et al. GCN 13438), we tentatively identify z=1.405 as the most likely GRB redshift.