GCN Circular 23173
Subject
GRB 180823A: Swift/UVOT Upper Limits
Event
Date
2018-08-24T16:26:22Z (8 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 180823A: Swift/UVOT Upper Limits
S. Sebzda (PSU) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180823A
381 s after the BAT trigger (Sbarufatti et al., GCN Circ. 23169).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 23170)
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 initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 381 417 36 >19.1
white 381 4476 380 >20.9
v 4686 10356 927 >19.2
b 4071 4271 197 >19.7
u 3866 4066 197 >19.8
m2 10361 10803 435 >19.8
w2 4482 4681 197 >20.0
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).