GCN Circular 22691
Subject
GRB 180504A: Swift/UVOT Upper Limits
Date
2018-05-07T14:52:23Z (6 years ago)
From
Jeffrey Gropp at PSU <jdg44@psu.edu>
J. D. Gropp (PSU), S. J. LaPorte (PSU), and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180504A
118 s after the BAT trigger (Lien et al., GCN Circ. 22682).
No optical afterglow consistent with the enhanced XRT position
(Evans GCN Circ. 22683)
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
b 5159 6793 116 >19.04
uvm2 5978 7606 136 >18.81
u_FC 302 6588 688 >19.53
u 705 1869 381 >19.47
v 631 651 136 >18.20
uvw1 6183 6383 136 >18.58
uvw2 5569 7204 136 >18.87
white_FC 143 6998 557 >20.67
white 582 1746 393 >20.46
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).