TITLE: GCN CIRCULAR NUMBER: 6541 SUBJECT: GRB 070612B: optical observations DATE: 07/06/16 09:01:57 GMT FROM: Giuseppe Greco at U Bologna G. Greco (Bologna University), F. Terra (Second University of Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University), G. Pizzichini (INAF/IASF Bologna), D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"), R. Gualandi (Bologna Observatory) report: We imaged the field of GRB 070612B (Grupe et al., GCN 6511) with the 152 cm Loiano telescope in the Rc and Ic filters in clear sky conditions. We do not detect any new sources in the combined images within the XRT error box (Grupe and Evans, GCN6521) with the following upper limits: tmid (UT) filter Exp. Limit June 13.917 Rc 3x1800 22.2 (3 sigma) June 13.975 Ic 3x1200 22.0 (3 sigma) We detect the faint source indicated by Cenko et al. (GCN 6521) at an Ic-band magnitude of 21.9+/-0.16 Magnitude and upper limits were estimated by comparison with the USNO-B1 stars and are not corrected for galactic dust extinction. The co-added Ic image, in which the comparison stars are marked, has been posted in our public directory from where it can be retrieved by sftp using hostname: ermione.bo.astro.it username: publicGRB password: GRB_bo. directory: GRB070612B [GCN OPS NOTE(17jun07): Per author's request, the reference to "GCN 6517" was corrected to "GCN 6521", and "GCN6514" was corrected to "GCN 6521".]