TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3526 SUBJECT: GRB050607 optical limit by "Pi of the Sky" DATE: 05/06/07 12:21:26 GMT FROM: Grzegorz Wrochna at Soltan Inst.for Nuclear Studies M.Cwiok, K.Krupska, K.Kwiecinska, L.Mankiewicz, M.Molak, K.Nawrocki, L.W.Piotrowski, M.Sokolowski, J.Uzycki, G.Wrochna, on behalf of "Pi of the Sky" collaboration http://grb.fuw.edu.pl "Pi of the Sky" apparatus has moved to the Swift-BAT trigger 132247 and it has taken series of 10s exposures starting 60s after the GRB (40s after the alert). No new object has been found within the Swift-BAT error box. The limiting magnitude is 11.5m (unfiltered) for single exposures and 12.5m for the sum of 10 images. However, the GRB counterpart might be hidden in the glow of 10.2m star GSC 01071-00926 (BD +8 4298), which is within the error box.