TITLE: GCN CIRCULAR NUMBER: 10512 SUBJECT: GRB 100316D: VLT/X-shooter observations DATE: 10/03/17 03:05:25 GMT FROM: Paolo D'Avanzo at INAF-OAB S.D. Vergani (GEPI-Obs. Paris), P. D'Avanzo (INAF-OAB), A.J. Levan (Univ. Warwick), S. Covino (INAF-OAB), D. Malesani, J. Hjorth (DARK/NBI), L.A. Antonelli (INAF-OAR) report on behalf of a larger collaboration: We observed the field of GRB 100316D (Stamatikos et al., GCN 10496) with the VLT equipped with the X-shooter spectrograph. Observations started on 2010 Mar 17 at 00:58 UT (~ 12 hours after the GRB). In the 100s acquisition image, we detect an object inside the XRT error circle, at the following position (J2000): RA: 07:10:30.77 Dec: -56:15:20.7 (+/- 0.5"). The object has a magnitude R~21 (calibrated against USNO-B1.0) and is very close (~3.5") to the DSS galaxy reported by Sakamoto et al. (GCN 10511). In the X-shooter spectrum of this source we detect several bright emission lines. Among these we have [OII], Hdelta, Hgamma, Hbeta, [OIII], Halpha all at a common redshift of 0.059. At present, we cannot say if this object (that might be a region of the nearby galaxy) is related with GRB 100316D. Further analysis and observations are in progress. We caution that the above analysis (particularly the wavelength solution) is preliminary. Reduction with updated calibrations is underway. We would like to thank the ESO staff for their kind assistance, in particular Thomas Rivinius, Alvaro Alvarez and Andres Pino