[vsnet-grb-info 3002] GRB 060223b: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4839
SUBJECT: GRB 060223b: Swift/UVOT Upper Limits
DATE:    06/02/27 15:33:11 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps at mssl.ucl.ac.uk>

P. Schady (PSU/MSSL-UCL), J.R. Cummings (NASA/ORAU), P.Brown (PSU), A. 
Cucchiara (PSU) on behalf of the Swift/UVOT team

The Swift/UVOT began observing the field of GRB 060223b at 16:23:16 UT on 24th 
February 2006, ~22hrs after the BAT trigger (Cummings et al. GCN 4821). 
Due to the proximity of a Mira variable star (~5th mag) observations were 
not made in the V or B filters. No source is detected at the refined XRT 
position (Perri et al. GCN 4835) in any of the other filters. The 3 sigma 
upper limits from a set of three coadded exposures in each filter are as 
follows:

Filter	T_mid(hrs)  Exp(s)  3sigUL(mag)
U	22.6        2300	20.5
UVW1	22.0        2522        20.8
UVM2	21.8        2524        21.1
UVW2    21.1        2524	21.3

T_mid is the mid-time of the set of coadded images relative to the time since 
the BAT trigger. We note that this is a very crowded field with a high level of 
Galactic extinction (E(B-V) = 0.393). All reported magnitudes are uncorrected 
for Galactic extinction.