TITLE: GCN CIRCULAR NUMBER: 14757 SUBJECT: GRB 130603B: VLT/X-shooter redshift confirmation DATE: 13/06/04 10:38:37 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Malesani (DARK/NBI), S. Schulze (PUC and MCSS), J. P. U. Fynbo, D. J. Watson (DARK/NBI), V. D'Elia (ASI-SDC, INAF OAR), P. Goldoni (APC, CEA/Irfu), M. Vestergaard (DARK/NBI) report on behalf of the X-shooter GRB GTO collaboration: We observed the optical afterglow of the short-duration GRB 130603B (Melandri et al., GCN 14735; Levan et al., GCN 14742; de Ugarte Postigo et al., GCN 14743) using the ESO VLT equipped with the X-shooter spectrograph. The observations started on 2013-06-04 at 00:00:28 UT (i.e., 8.187 hr after the burst). A total exposure of 4x600 s was obtained, covering the spectral range from ~300 to ~2100 nm. A continuum is detected in all the UVB/VIS/NIR arms of the spectra. We identify several absorption features which we interpret as Ca II H & K and Mg II from the optical afterglow, as well as emission lines such as the [O II] doublet, [O III], H-alpha, H-beta, and [S II] from the host galaxy, all at a common redshift of z=0.3564+/-0.0002, fully consistent with the measurements by Thoene et al. (GCN 14744), Foley et al. (GCN 14745), and Sanchez-Ramirez et al. (GCN 14747). We thank the Paranal staff for enthusiastic support, in particular Cedric Ledoux and Alex Correa.