TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4917
SUBJECT: GRB 060323: Swift/UVOT Observations
DATE:    06/03/24 20:56:10 GMT
FROM:    Frank Marshall at GSFC  <marshall@milkyway.gsfc.nasa.gov>

F. Marshall (GSFC/NASA) and L. Vetere (ASDC) on behalf of the Swift/UVOT team

The Swift/UVOT began taking data on the field of GRB 060323 at 14:37:30 UT on 
2006-03-23, approximately 294s after the BAT trigger (Vetere et al., GCN 4904). 
There are marginal detections at the position of the optical afterglow 
(Covino et al. GCN 4911; Jensen et al. GCN 4915; Covino et al. GCN 4916)
in the White, V, and B filters. The table below provides the results
for the initial finding chart exposure using the White filter and for
summed exposures.

The UVOT on-board detection of a weak source suggested as a possible afterglow
by Vetere et al. is not confirmed in ground analysis of the complete 
finding chart image.

Filter	T_range(s)  Exp(s)  3-sigma UL   Possible Detection
                                            Mag   sigma
White   294-393      100     20.0          21.1   1.8
White   486-17446   2171     21.9
V       525-22318   2012     20.6          21.6   2.1
B       473-16535   1308     21.3          22.1   2.6
U       449-6313     453     21.2
UVW1    425-23955   1163     21.3

These magnitudes are uncorrected for the expected Galactic extinction corresponding
to E(B-V) = 0.015.