TITLE:   GCN CIRCULAR
NUMBER:  31682
SUBJECT: GRB 220302A: Swift/UVOT Upper Limits 
DATE:    22/03/05 03:37:18 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

M. H. Siegel (PSU) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220302A
32464 s after the BAT trigger (Troja et al., GCN Circ. 31661).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 31666) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC         32464        32614          147         >19.9
white            32464        32614          147         >19.9
v                32621        33528          885         >19.2
m2               33533        34194          651         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.217 in the direction of the burst
(Schlegel et al. 1998).