GCN Circular 10087
Subject
GRB 091026: Swift/UVOT Upper Limits
Date
2009-10-26T22:38:01Z (15 years ago)
From
Peter Curran at MSSL <pac@mssl.ucl.ac.uk>
P.A. Curran (MSSL-UCL) and C.B. Markwardt (CRESST/GSFC/UMD)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091026 87 s
after the BAT trigger (Markwardt et al., GCN 10081). No optical afterglow
consistent with the enhanced XRT position (Evans et al., GCN 10084) is
detected in the initial UVOT exposures. Preliminary 3-sigma upper limits
using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for
the first finding chart (FC) exposures and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
-----------------------------------------------------------
white (FC) 87 237 147 >21.00
u (FC) 300 550 246 >20.36
white 87 12292 950 >22.09
v 629 5959 236 >19.63
b 555 6778 235 >20.62
u 300 6573 462 >20.72
w1 678 6369 236 >20.09
m2 826 6164 216 >19.85
w2 605 16097 561 >20.70
The values quoted above are not corrected for the Galactic extinction due
to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel
et al. 1998).