GCN Circular 23215
Subject
GRB 180905A: Swift/UVOT Upper Limits
Date
2018-09-09T19:37:38Z (6 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H. Siegel (PSU) and V. D'Elia (SSDC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180905A
154 s after the BAT trigger (D'Elia et al., GCN Circ. 23201).
No optical afterglow consistent with the XRT position
(D'Elia et al. GCN Circ. 23201) is detected in the initial UVOT exposures,
as confirmed by Bootes (Hu et al., GCN Circ. 23208), MITSUME (Niwano
et al., GCN Circ. 23211) and RATIR (Watson et al., GCN Circ. 23212).
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 154 289 133 >20.4
white 154 6385 373 >21.1
v 5316 5515 197 >19.1
b 4700 6335 393 >20.5
u 4495 6130 393 >20.3
w1 5726 5925 197 >19.6
m2 5520 5720 197 >19.8
w2 5111 5311 197 >19.2
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.60 in the direction of the burst
(Schlegel et al. 1998).