Back

GCN Circular 22912

Subject

GRB 180705A: Swift/UVOT Upper Limits

Date

2018-07-06T10:11:35Z (6 years ago)

From

Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL), S. W. K Emery (UCL-MSSL) and M. Stamatikos 
(OSU/NASA/GSFC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180705A
3368 s after the BAT trigger (Stamatikos et al., GCN Circ. 22902Not found
 
 
).
No optical afterglow consistent with the enhanced XRT position (Goad et 
al. GCN Circ. 22906Not found
 
 
) 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          3368         3485          115         >20.2
white             3368         5327          312         >20.8
v                 4103         5738          393         >18.9
b                 4923        11649          311         >20.5
u                 4718        11527         1082         >21.0
w1                4513        16889          483         >20.5
m2                4308        15205          647         >20.1
w2                5333         5533          197         >20.4

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.06 in the direction of the 
burst (Schlegel et al. 1998).