[vsnet-grb-info 10101] GRB 110107A: Swift/UVOT upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11551
SUBJECT: GRB 110107A: Swift/UVOT upper limits
DATE:    11/01/10 19:20:46 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler at nasa.gov>

S. Immler (CRESST/UMCP/GSFC) and G. Stratta (ASDC) report on behalf
of the Swift/UVOT team:

Swift UVOT started observing the field of GRB 110107A on January 8,
2011 at 15:12 UT, approximately T+17.9 hours (Cummings, GCN Circ 11545).

No optical afterglow consistent with the XRT position (Stratta et al.,
GCN Circ. 11547) is detected in individual or merged UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) are:

Filter      T_start   T_stop    Exp(s)      Mag
-----------------------------------------------
v            64,646   75,090      2247 >20.5
u            64,609   74,538      1638 >21.2
-----------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.459 mag (Schlegel et al., 1998, ApJS, 500, 525).