GCN Circular 22898
Subject
GRB 180703A: Swift/UVOT Upper Limits
Event
Date
2018-07-04T17:04:13Z (8 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180703A
17269 s after the Fermi/LAT trigger (Racusin et al. GCN Circ. 22883).
No optical afterglow consistent with the XRT position of the
uncatalogued X-ray source, source 1 (Gibson et al. GCN Circ. 22891)
or the position from LCO Sutherland (Guidorzi et al. GCN Circ. 22892)
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
exposures at the position of source 1 are:
Filter T_start(s) T_stop(s) Exp(s) Mag
b 17353 28862 47 >19.2
u 17323 28834 116 >19.5
uvw1 17269 28807 234 >19.8
uvw2 17384 28917 97 >19.2
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).