TITLE:   GCN CIRCULAR
NUMBER:  33003
SUBJECT: GCN: GRB 221201A: Swift/UVOT Upper Limits
DATE:    22/12/02 13:27:29 GMT
FROM:    Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U.Birmingham) 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 221201A
179 s after the BAT trigger (Troja et al., GCN Circ. 32998).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 33001)
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           179          329          147         >20.1
white              179         1970          225         >20.2
v                 1479         2020           78         >17.8
b                 1404         2107           85         >18.8
u                  337         2094          277         >19.2
w1                1529         2069           78         >18.4
m2                1504         2045           78         >18.5
w2                1454         1996           78         >18.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.066 in the direction of the burst
(Schlegel et al. 1998).