GCN Circular 29978
Subject
GRB 210509A: Swift/UVOT Upper Limits
Event
Date
2021-05-10T10:10:56Z (5 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210509A
3202 s after the BAT trigger (Page et al., GCN Circ. 29970).
No optical afterglow consistent with the XRT position (Evans et al.
GCN Circ. 29971) 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 3202 3352 147 >20.8
white 3202 4585 344 >21.0
v 3358 4934 332 >19.0
b 4180 4380 197 >19.5
u 3974 4174 197 >19.6
w1 3769 3969 197 >19.5
m2 3563 3763 197 >20.3
w2 4592 4792 197 >19.6
The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.074 in the direction of
the burst (Schlegel et al. 1998).