GCN Circular 16717
Subject
GRB 140818B: Swift/UVOT Upper Limits
Event
Date
2014-08-19T13:10:44Z (12 years ago)
From
Lea Hagen at PSU <lea.zernow.hagen@gmail.com>
L. M. Z. Hagen (PSU) and A. Vargas (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140818B
114 s after the BAT trigger (Vargas et al., GCN Circ. 16709). No optical
afterglow consistent with the XRT position (Beardmore et al. GCN Circ.
16712), the OSN candidate (Aceituno et al. GCN Circ 16711), or the GROND
candidate (Knust et al. GCN Circ 16713) 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 early
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 113 5136 530 >21.32
v 654 5546 254 >19.28
b 581 4931 235 >20.11
u 325 6007 506 >20.17
uvw1 704 5956 416 >19.92
uvm2 5551 5751 196 >19.53
uvw2 803 5341 235 >19.97
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.70 in the direction of the burst
(Schlegel et al. 1998).