GCN Circular 22181
Subject
GRB 171205A: Swift/UVOT Detection
Event
Date
2017-12-05T13:45:32Z (8 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171205A
154 s after the BAT trigger (D'Elia et al., GCN Circ. 22177).
A source consistent with the XRT position
(J.P. Osborne et al. GCN Circ. 22179)
is detected in the initial UVOT exposures.
There is marginal evidence for brightening in the white filter.
The revised source position is
RA(J2000)=11:09:39.547 Dec.(J2000)=-12:35:17.93. This position
is within the XRT error circle and is consistent with the VLT/X-shooter
optical position (L. Izzo et al. GCN Circ. 22180).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 154 303 147 18.10 +/- 0.08
white 3812 3849 36 17.70 +/- 0.09
u 312 390 78 17.78 +/- 0.18
v 4499 4698 197 18.22 +/- 0.15
b 3607 3807 197 18.45 +/- 0.09
uvw1 4908 5108 197 17.13 +/- 0.09
uvm2 4703 4903 197 17.11 +/- 0.11
uvw2 4294 4494 197 16.96 +/- 0.10
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998), nor from any contribution of the host galaxy.