TITLE: GCN CIRCULAR NUMBER: 9464 SUBJECT: Initial Swift/UVOT observations of GRB 090531B DATE: 09/05/31 20:49:26 GMT FROM: Caryl Gronwall at PSU/Swift-UVOT C. Gronwall (PSU) and J. R. Cummings (NASA/UMBC) report on behalf of the UVOT Team: In response to GRB090531B (Swift/BAT trigger 353728; Cummings et al., GCN Circ. 9461) at 18:35:56 UT, UVOT took a finding chart exposure of 150 seconds with the White filter starting 3848 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle (Sbarufatti et al., GCN Circ. 9463) The typical 3-sigma upper limit has been about 19.6 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 1.12.