TITLE:   GCN CIRCULAR
NUMBER:  11769
SUBJECT: Swift/UVOT observations of GRB110223A
DATE:    11/02/24 23:12:30 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale (MSSL-UCL) and T. Sakamoto (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110223A
97 s after the BAT trigger (Sakamoto et al., GCN Circ. 11753).
No optical afterglow consistent with the XRT enhanced position
(Evans et al., GCN circ. 11759) is detected in the initial UVOT exposures
nor in the summed exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

Filter       T_start(s)    T_end(s)   Exp     Magnitude

white (fc)        97          246     147	>20.81
white             97         5588     344	>21.16

v                639         5998     217	>19.40

b                565         5383     216	>20.00

u (fc)           310          559     196	>19.41
u                310         5177     443	>20.15

uw1             4773         6408     393	>20.13

um2              663         6203     412	>20.14

uw2              615         5794     216	>19.89

The above magnitudes are not corrected for the strong Galactic
extinction along the line of sight, corresponding to E(B-V) = 0.34
(Schlegel et al. 1998).