[vsnet-grb-info 12583] GRB 121031A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13947
SUBJECT: GRB 121031A: Swift/UVOT Upper Limits
DATE:    12/11/02 18:26:47 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121031A
70 s after the BAT trigger (D'Elia et al., GCN Circ. 13934).
No optical afterglow consistent with the enhanced XRT position
(Goad et al., GCN Circ. 13944) 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            70          220          147         >19.9
white             5366         7002          393         >20.5
v                 5776        11730          787         >19.4
b                 5161        18152          492         >20.0
u                16939        17239          295         >19.5
w1                4751        16932         1279         >20.5
m2                4545        22572         1870         >21.1
w2                5572        11120         1082         >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).