TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5228 SUBJECT: GRB060605: Swift/UVOT detections DATE: 06/06/06 11:50:44 GMT FROM: Alexander Blustin at MSSL-UCL A. J. Blustin (UCL-MSSL) and M. J. Page (UCL-MSSL) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB060605 at 18:17:21 on 2006-06-05, 97 s after the BAT trigger (Page et al., GCN 5221). An optical afterglow was detected at (RA,DEC) (J2000) of (21h28m37.32s,-06o03'31.3") with a 1-sigma error radius of about 0.5 arcsec, in the V, B and White filters, which is consistent with the redshifts of 3.8 (Peterson et al., GCN 5223) or 3.7 (Still et al., GCN 5226) already reported for this GRB. Magnitudes and three-sigma upper limits are as follows: Filter T_range(s) Exp(s) Mag/3sig_UL V 202-595 386 16.53 +/- 0.04 V 10172-10471 291 19.0 +/- 0.2 B 4388-4588 190 20.0 +/- 0.2 B 23023-23322 287 21 +/- 1 U 4184-23017 2140 21.1 (3sig_UL) UVW1 3979-22104 2030 20.2 (3sig_UL) UVM2 3774-11377 1267 20.7 (3sig_UL) UVW2 4798-6381 338 19.9 (3sig_UL) White 97-197 98 17.64 +/- 0.06 White 17477-17776 291 20.5 +/- 0.3 These values are not corrected for the estimated Galactic extinction of E(B-V) = 0.049.