TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4814
SUBJECT: GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
DATE:    06/02/23 08:08:32 GMT
FROM:    Padi Boyd at GSFC  <padi@milkyway.gsfc.nasa.gov>

F. Marshall (GSFC) P. Boyd (GSFC), M. Chester (PSU), J. Cummings (ORAU)
on behalf of the Swift/UVOT team report:

We have further analyzed the four individual finding chart sub-images
sent via TDRSS from the Swift UVOT containing the afterglow of
GRB 060223 (Cummings et al., GCN 4813).

The source is detected in the first 3 finding charts with an
upper limit in the fourth finding chart as follows:


Filter  T_start(s)      Exp(s)  (mag/UL (detection significance))

V       86              200     18.0 +/- 0.14 (10 sigma)
B       293             200     21.0     0.5  (2.5 sigma)
V       835             200     19.6     0.4  (3.5 sigma)
B       1042            200    >21.3          (2 sigma)

Reported times are in seconds since the BAT trigger.
These magnitudes are uncorrected for the expected
Galactic extinction corresponding to E(B-V) = 0.12.

We note that the higher than expected B-V inferred from the first
three images could be caused by a redshift of z=3.3 or greater.