GCN Circular 29615
Subject
GRB 210305A: Swift/UVOT Upper Limits
Date
2021-03-07T19:43:36Z (3 years ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
A. Belles (PSU) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210305A
85 s after the BAT trigger (D'Ai et al., GCN Circ. 29595).
No optical afterglow consistent with the XRT position
(D'Ai et al. GCN Circ. 29595)
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 86 235 147 >20.19
u_FC 298 548 245 >19.54
white 577 1721 264 >20.51
v 627 1771 134 >18.55
b 553 1696 116 >19.37
u 700 1672 97 >18.86
w1 676 1818 134 >18.70
m2 651 1795 136 >18.63
w2 603 1746 136 >18.60
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.155 in the direction of the burst
(Schlegel et al. 1998).