TITLE:   GCN CIRCULAR
NUMBER:  10791
SUBJECT: Swift/UVOT observations of GRB100522A.
DATE:    10/05/22 23:38:54 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale (MSS-UCL) and Eleonora Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:

Swift/UVOT began settled observations of GRB100522A (Troja et al.
GCN Circ. 10784) starting 73 seconds after trigger. No optical afterglow
within the enhanced XRT position (Osborne et al. GCN Circ. 10787) is
detected in the UVOT 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 summed exposures are:

Filter   T_start(s)  T_stop(s)   Exp(s)   Mag
-----------------------------------------------------------
white       73         223         147      >20.1 (FC)
white       73        7223         569      >20.9
v          614        6199         352      >19.0
b          541        7018         352      >19.9
u          285       13630        1243      >20.1
uw1        663       12939        1242      >20.5
m2         639        7838         549      >20.2
w2         590        7429         363      >20.1


The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).