GCN Circular 8137
Antonio de Ugarte Postigo (ESO), Christina C. Thoene (DARK/NBI) and Davide Ricci (Univ. of Liege) report: We obtained further observations of the candidate optical counterpart of GRB 080825B (Evangelista et al., GCN 8133) in Bessel-UBVRI bands. The object is found to be fading in a series of I band images. From 23:18 UT to 01:41 UT, the candidate afterglow faded from 17.4+/-0.2 to 18.1+/-0.2 mag compared to several USNO-B stars, confirming the reality of the afterglow proposed by Thoene et al. (GCN 8135). Furthermore the object is detected in V, R and I band, but not in U and B. We therefore derive a redshift limit of z>3 if the nondetection is due to Lyman alpha absorption or z>4.3 if due to the Lyman limit. Further analysis is ongoing.