TITLE: GCN CIRCULAR NUMBER: 20858 SUBJECT: GRB 170311A: VLT observations DATE: 17/03/13 12:54:51 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), H. Flores (GEPI/Paris obs.), A. J. Levan (Univ. Warwick), D. Xu (NAOC/CAS), N. R. Tanvir (Univ. Leicester), and J. P. U. Fynbo (DARK/NBI), report: We observed the field of GRB 170311A (Cummings et al., GCN 20846) with the VLT/UT2 (Kueyen), using the acquisition camera of the X-shooter spectrograph. Observations started approximately on March 11.366 UT, that is around 38 min after the GRB trigger. Imaging was carried out using the SDSS z filter. No source is detected within or close to the UVOT-enhanced XRT position (Osborne et al., GCN 20850), down to a 3-sigma limiting magnitude z = 21 AB, calibrated against nearby stars from the Pan-STARRS catalog (Chambers et al. 2016, arXiv: 1612.05560). Our result is consistent with other reports (e.g., Wiseman & Schady, GCN 20853). We acknowledge excellent support from the ESO observing staff at Paranal, in particular Marcelo Lopez, Joe Anderson, and George Hau. We also acknowledge the team of the Gaia-ESO survey (ESO program 197.B-1074, PI Gilmore), for generously and consistently accepting to carry out ToO observations during their allocated nights.