GCN Circular 30552
Subject
GRB 210730A: Swift/UVOT Upper Limits
Date
2021-07-30T13:13:09Z (3 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (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 210730A
90 s after the BAT trigger (Sonbas et al., GCN Circ. 30548).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 30550)
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 90 204 112 >17.0
white 90 4145 308 >16.7
v 4355 4555 197 >15.5
b 3740 3940 197 >16.4
u 3535 5146 370 >16.5
w1 4765 4965 197 >18.0
m2 4560 4760 197 >19.7
w2 4151 4351 197 >18.6
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).