[vsnet-grb-info 19425] GRB 170524A: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21141
SUBJECT: GRB 170524A: Swift/UVOT Upper Limits
DATE:    17/05/25 12:37:02 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15 at ucl.ac.uk>

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

The Swift/UVOT began settled observations of the field of GRB 170524A
67 s after the BAT trigger (Gropp et al., GCN Circ. 21135).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 21136)
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            67          217          147         >20.4
u_FC               280          529          246         >19.5
white               67         1007          334         >20.6
v                  610         1058           58         >17.9
b                  535         1157           58         >18.7
u                  280         1132          285         >19.5
w1                 660         1107           58         >18.3
m2                1063         1082           19         >17.3
w2                 586         1033           58         >18.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.82 in the direction of the burst
(Schlegel et al. 1998).