TITLE: GCN CIRCULAR NUMBER: 15447 SUBJECT: GRB 131105A: VLT/X-shooter optical afterglow candidate DATE: 13/11/05 04:20:01 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), D. Malesani (DARK/NBI), N. R. Tanvir (U. Leicester), T. Kruehler (ESO), report on behalf of a larger collaboration: We observed the field of GRB 131105A (Cummings et al., GCN 15446) with the acquisition camera of the X-shooter spectrograph at the VLT. The observation was taken around 03:24 UT on November 5, that is 1.3 hr after the GRB. Inside the current XRT error circle (2.0" radius; see http://www.swift.ac.uk/xrt_positions/), we detect a single source at coordinates (J2000): RA = 04:43:52.27 Dec = -62:59:43.7 with an uncertainty of <0.5". Its magnitude is R = 22.4 +- 0.1, compared to three nearby bright USNO stars. At the moment we cannot conclude whether this source is variable or associated to the GRB, but we propose it as a candidate counterpart. We acknowledge excellent support from the ESO staff in Paranal, in particular Dimitri Gadotti and Roger Wesson.