GCN Circular 23080

Subject

GRB 180805B: Swift/UVOT Upper Limits

Event

Date

2018-08-05T22:12:32Z (7 years ago)

From

Paul Kuin at MSSL <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 180805B  85 s after the BAT trigger (D'Avanzo et al.,
GCN Circ. 23076Loading...
 
 ).  No optical afterglow consistent with the
XRT position (Evans et al. GCN Circ. 23077Loading...
 
 ) 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            85          235          147         >20.8
u_FC               297          546          246         >20.2
white               85         1544          392         >21.3
v                  626         1421           78         >18.6
b                  552         1519           97         >20.0
u                  297          546          246         >20.2
w1                 675         1470           97         >18.8
m2                1078         1097           19         >17.8
w2                 774         1569           78         >19.0

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).