TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4824 SUBJECT: GRB 060223a: Swift/UVOT refined analysis DATE: 06/02/24 02:02:39 GMT FROM: Alexander Blustin at MSSL-UCL A. J. Blustin (UCL-MSSL), J. R. Cummings (NASA/ORAU) report on behalf of the Swift/UVOT team: The Swift/UVOT began observing the field of GRB 060223a 72 s after the BAT trigger, detecting a red afterglow (Cummings et al., GCN 4813; Marshall et al., GCN 4814). Analysis of a more complete dataset shows that V was the only band to yield a significant detection of the afterglow, as to be expected given the redshift of the burst (z=4.41; Berger et al., GCN 4815). The magnitudes and 3-sigma upper limits from all filters are listed below. Filter T_range (MET) Exp (s) Mag/3sigUL V 72-81 9 17.7 +/- 0.4 V 85-285 200 17.8 +/- 0.1 V 545-1034 239 19.4 +/- 0.3 V 1294-11097 512 >19.6 B 292-492 200 >20.2 B 641-7249 731 >20.9 U 616-7044 532 >20.4 UVW1 593-6839 355 >20.4 UVM2 569-6634 355 >20.9 UVW2 521-10892 580 >21.1 These are uncorrected for the estimated Galactic extinction corresponding to E(B-V) = 0.12