GCN Circular 9947
Johan P. U. Fynbo, Daniele Malesani (DARK/NBI), Pall Jakobsson (U. Iceland) and Valerio D'Elia (ASDC and INAF/OAR) report on behalf of a larger collaboration: We observed the afterglow of GRB 090926B (Grupe et al, GCN 9935; Morii et al., GCN 9943). Using FORS2 on the Very Large Telescope, we have obtained 3*30 min spectra (300V grating) of the optical afterglow candidate (Malesani et al., GCN 9944). Observations commenced roughly 8 hours after the burst. The combined spectrum shows an emission line, presumably corresponding to [O II] 3727 at z = 1.24. At his redshift we find several other absorption features, including Mg II, Fe II and Al III. Hence, we interpret the spectrum as a combination of the GRB afterglow and the host galaxy. We acknowledge excellent support from the ESO observing staff, in particular Yuri Beletsky and Stephane Brillant.