GCN Circular 28400
Subject
GRB 200907B: Swift/UVOT Upper Limits
Event
Date
2020-09-09T03:50:55Z (6 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200907B
84 s after the BAT trigger (Beardmore et al., GCN Circ. 28384).
No optical afterglow consistent with the XRT position
(Evans GCN Circ. 28385) 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 84 233 147 >20.4
u_FC 296 546 246 >19.7
white 84 4892 383 >21.0
v 625 819 39 >17.7
b 551 4687 236 >19.4
u 296 4482 462 >20.4
w1 675 4277 216 >19.2
m2 650 670 19 >18.3
w2 601 5048 186 >19.2
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.61 in the direction of the burst
(Schlegel et al. 1998).