GCN Circular 30529
Subject
GRB 210724A: Swift/UVOT Upper Limits
Event
Date
2021-07-27T06:17:13Z (5 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 210724A: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210724A
125 s after the BAT trigger (D'Avanzo et al., GCN Circ. 30497).
No optical afterglow consistent with the XRT position
(D'Avanzo et al. GCN Circ. 30497)
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 125 275 147 >20.8
u_FC 283 513 226 >20.1
white 125 275 147 >20.8
u 283 513 227 >20.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.097 in the direction of the burst
(Schlegel et al. 1998).