GCN Circular 17603
Subject
GRB 150318A: Swift/UVOT Upper Limits
Date
2015-03-18T13:52:59Z (9 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and C. Pagani (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150318A
151 s after the BAT trigger (Pagani et al., GCN Circ. 17599).
No optical afterglow consistent with the XRT position (Evans et al. GCN
Circ. 17600) 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 151 300 147 >20.8
u_FC 308 558 246 >19.8
white 151 5695 530 >21.4
v 638 6106 432 >20.0
b 736 6762 252 >20.4
u 308 6721 659 >20.4
w1 687 6516 413 >20.2
m2 4676 6311 393 >20.1
w2 4266 5901 393 >20.8
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.04 in the direction of the
burst (Schlegel et al. 1998).