[vsnet-grb-info 17697] GRB 160303A: Swift/UVOT Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19134
SUBJECT: GRB 160303A: Swift/UVOT Detection
DATE:    16/03/03 20:15:46 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15 at ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and A. P. Beardmore (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 160303A
109 s after the BAT trigger (Beardmore et al., GCN Circ. 19126).
We detect a fading source consistent with the XRT position
(Beardmore et al. GCN Circ. 19126) and the RATIR optical and NIR afterglow
detections (Butler et al. GCN Circ 19131)
in the initial UVOT u filter 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           109         259          147         >21.9
u_FC                   321         571          246          20.75
white                 109          2061        450         >22.5
b                         576          2037        136         >19.9
w1                      700          2161           77         >20.5
m2                     1426        1445           19         >19.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).