[vsnet-grb-info 17225] GRB 151111A: Swift/UVOT upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18587
SUBJECT: GRB 151111A: Swift/UVOT upper limits
DATE:    15/11/12 13:57:55 GMT
FROM:    Massimiliano de Pasquale at IASF-Palermo  <m.depasquale at ucl.ac.uk>

M. De Pasquale, S. Emery (UCL-MSSL) and L. M. McCauley (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 151111A
81 s after the BAT trigger (McCauley et al., GCN Circ. 18578).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 18579) 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            81           231          147 >20.9
u_FC                293           543          246 >19.7
white                 81         6778          519 >21.7
v                      622         7094          339 >19.7
b                      549         6573          235 >20.6
u                      293         6367          442 >19.7
w1                    671         6163          216 >20.0
m2                 5757         5957          197 >19.7
w2                   772         6984          413 >20.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).