TITLE:   GCN CIRCULAR
NUMBER:  17302
SUBJECT: GRB 150110C: Swift/UVOT Upper Limits
DATE:    15/01/11 21:11:33 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

Paul Kuin (MSSL/UCL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of MAXI GRB 150110C
54ks after the trigger.  No optical afterglow consistent with the XRT
position
(Page, GCN Circ. No. 17301)  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 initial exposures
are:

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

u                54238        59786         1896         >20.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).