TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3151 SUBJECT: GRB050326: optical limit DATE: 05/03/27 01:33:31 GMT FROM: Martin Jelinek at Inst.Astrophys.Andalucia,Granada P. Tristram (Univ. of Canterbury, New Zealand), M. Jelinek, A. de Ugarte Postigo, J. Gorosabel, A.J. Castro-Tirado, (IAA-CSIC, Granada, Spain), M. A. Castro Tirado (M?laga), J. M. Castro Cerón (Univ. of Copenhagen, Denmark) and Ph. Yock (Univ. of Auckland, New Zealand) report: We have imaged the error box provided by Swift (trigger 112453, GCN 3147) with the 0.6m telescope (+MOA camera) at Mt.John Observatory. A 600s second integration taken at 16:47:45 UT (ie. 6.90 hours after burst, mean obs. time) reveals no apparent source down to limiting mag. 20.3 in comparison with DSS. Observation was performed with MOA broad R-band filter (similar to Ic). [GCN OPS NOTE (28mar05): At an author's request "M. A. Castro Tirado (M?laga)" was added to the author list.]