GCN Circular 7587
Christina C. Thoene (DARK/NBI), Annalisa De Cia (Univ. Iceland), Daniele Malesani, and Paul M. Vreeswijk (DARK/NBI), report: We observed the optical afterglow of GRB 080411 (Marshall et al., GCN 7584; Kruehler et al., GCN 7586) wih the ESO VLT equipped with FORS1 with grism 300V. In a 600 s exposure taken at large airmass (average of 2.45) the afterglow trace is clearly detected. The mean time of the observations is Apr 11.987 UT (2.4 hr after the trigger). In the acquisition image, we measure R = 17.25 based on archival zeropoints. We detect very strong absorption lines from Mg II, Mg I, Fe II and several other ions at a redshift z = 1.03. Given the strength of the features, we consider this to be the redshift of the GRB. We caution that the wavelength calibration is based on archival data. We acknowledge excellent support from the ESO staff, who carried out this difficult observation, in particular Swetlana Hubrig.