TITLE:   GCN CIRCULAR
NUMBER:  15288
SUBJECT: GRB 131001A: Swift UVOT and XRT Upper Limits 
DATE:    13/10/02 17:32:47 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <dxg35@psu.edu>

A. A. Breeveld (UCL-MSSL), D. Grupe (PSU) and J. R. Cummings
(UMBC/GSFC) report on behalf of the Swift team:

The Swift/UVOT began settled observations of the field of GRB 131001A
79990 s after the BAT trigger (Cummings et al., GCN Circ. 15281).
No optical afterglow consistent with the BAT position (Cummings et al.,
GCN Circ. 15281) 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                79990        86246          972         >20.94

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.03 in the direction of
the burst (Schlegel et al. 1998).

The Swift XRT observed the field of GRB 131001A for a total of 972s. 
No source was found in the BAT error circle. The 3 sigma upper limit
at the position of GRB 131001A applying the method described in Kraft
et al. (1991, ApJ, 374, 344) is 0.01 counts/s.

This circular is an official product of the Swift team.