TITLE:   GCN CIRCULAR
NUMBER:  28613
SUBJECT: GRB 201013A: Swift/UVOT Upper Limits
DATE:    20/10/13 19:41:14 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201013A 74 s after the BAT trigger 
(Page et al., GCN Circ. 28607).
There is a bright optical source (USNO B1.0 1470-0207304) 0.5 arcsec from the enhanced XRT position 
(Beardmore et al. GCN Circ. 28608). The magnitudes measured at this position by UVOT are consistent 
with those catalogued and thus we do not detect any evidence of an afterglow candidate.
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            74          223          147         >16.8
u_FC               286          535          246         >16.7
white               74         1712          412         >16.8
v                  616         1763          136         >16.2
b                  541         1686          117         >16.6
u                  286         1662          343         >16.7
w1                 665         1804          127         >16.6
m2                 640         1611           58         >16.7
w2                 591         1738          136         >17.1

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).