GCN Circular 22893
Subject
GRB 180704A: Swift/UVOT Upper Limits
Date
2018-07-04T13:31:43Z (6 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.) and
A. A. Breeveld (UCL-MSSL)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180704A
3255 s after the BAT trigger (Sonbas et al., GCN Circ. 22885).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 22890)
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
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 3255 5455 537 >20.8
v 4233 10567 1082 >19.8
b 3618 5253 393 >19.9
u 3413 5048 393 >19.6
uvw1 4643 4843 197 >19.2
uvm2 4438 11190 804 >20.3
uvw2 4028 9654 1082 >20.7
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.87 in the direction of the burst
(Schlegel et al. 1998).