[vsnet-grb-info 21198] GRB 181002A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23297
SUBJECT: GRB 181002A: Swift/UVOT Upper Limits
DATE:    18/10/03 10:48:04 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15 at ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 181002A
144 s after the BAT trigger (Gropp et al., GCN Circ. 23290).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 23292)
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           144          294          147         >20.8
u_FC               302          552          246         >20.3
white              144         1008          334         >20.7
v                  632         1058           58         >17.9
b                  558          751           39         >18.6
u                  302          726          265         >20.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.60 in the direction of the burst
(Schlegel et al. 1998).