GCN Circular 22827
Subject
GRB 180620B: Swift/UVOT Detection
Date
2018-06-23T11:44:09Z (6 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL), P. A. Evans (U. Leicester) and M. De Pasquale
(U. Instanbul) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180620B 92
s after the BAT trigger (Evans et al., GCN Circ. 22807).
A source consistent with the enhanced XRT position (Beardmore et al.,
GCN Circ. 22814) and the Grond position (Schweyer and Schady, GCN Circ.
22819), and also detected by Izzo et al. (GCN Circ. 22823) is detected
in the initial UVOT exposures in all filters except uvw2. The
non-detection in the uvw2 filter is consistent with the redshift of 1.12
(Izzo et al. GCN Circ. 22823).
Preliminary detections and 3-sigma upper limits 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 92 242 147 18.06 �� 0.08
v 634 826 39 17.41 �� 0.22
b 559 579 20 17.56 �� 0.18
u 304 554 246 17.40 �� 0.09
uvw1 9950 18219 1394 20.17 �� 0.2
uvm2 6563 16382 804 20.6 �� 0.3
uvw2 4256 4443 183 > 19.7
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.01 in the direction of the
burst (Schlegel et al. 1998).