TITLE: GCN CIRCULAR NUMBER: 6526 SUBJECT: GRB 070612A: MDM Observations DATE: 07/06/13 04:38:28 GMT FROM: Nestor Mirabal at Columbia U N. Mirabal, I. D. McGreer, J. P. Halpern (Columbia U.), M. Dietrich, B. M. Peterson (Ohio State U.) report on behalf of the MDM GRB follow-up team: "We observed the candidate optical afterglow of Swift GRB 070612A (Updike et al. GCN 6515, Cenko et al. GCN 6525) using the MDM 2.4m telescope. Preliminary calibration with respect to USNO magnitudes of nearby stars yields r' ~ 19.0 +/- 0.3 on June 13 03:59 UT and i' ~ 18.4 +/- 0.2 on June 13 03:49 UT respectively. These measurements indicate that the afterglow has faded with respect to previous reports."