TITLE: GCN CIRCULAR NUMBER: 7770 SUBJECT: GRB 080523: VLT optical observations DATE: 08/05/24 14:32:01 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center Johan P. U. Fynbo, Daniele Malesani (DARK), Pall Jakobsson (Univ. Hertfordshire), Bo Milvang-Jensen and Jens Hjorth (DARK), report on behalf of a larger collaboration: We observed the field of GRB 080523 (Stroh et al., GCN 7767) with the ESO VLT equipped with FORS2. Photometric observations were conducted on 2008 May 24, between 8:14 and 8:27 UT (about 10.9 hr after the GRB). Inside the revised XRT error circle (Osborne et al., GCN 7768), we detect a faint source at coordinates (J2000): RA = 01:23:11.61 Dec = -64:01:51.8 Lacking any information on variability, we cannot assess whether this source is associated with GRB 080523. A spectrum of the object shows detection of continuum in the blue down to 4200 AA, implying a redshift limit z < 2.5. Further analysis is underway. We note the presence of two further, faint sources close to, but slightly outside of, the refined XRT error circle at (RA, Dec) = (01:23:11.21, -64:01:53.9) and (01:23:10.88, -64:01:50.4). We acknowledge excellent support and positive initative from the ESO observing staff, particularly Yuri Beletsky and Patricia Guajardo.