GCN Circular 9309
Subject
GRB 090429B: Swift/UVOT Upper Limits
Date
2009-04-30T16:03:10Z (15 years ago)
From
Margaret Chester at PSU <chester@astro.psu.edu>
M. M. Chester (PSU) and T. N. Ukwatta (GSFC/GWU) report on the behalf
of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 090429B starting 78 s
after the BAT trigger (Ukwatta et al. 2009, GCN Circ. 9281). Settled
exposures started at T+99 s. We do not find any new source at the
position of the XRT afterglow (Beardmore et al. 2009, GCN Circ. 9288).
Preliminary 3-sigma upper limits for detecting a source in the white
finding chart and the co-added images, using a 5 arcsecond radius
circular aperture, are:
Filter T_start T_stop Exp(s) Mag
----------------------------------------------
white (fc) 99 249 150 >21.0
white 591 10856 1241 >22.2
v 640 12550 1213 >20.6
b 567 6769 381 >20.8
u 311 6621 669 >20.8
uvw1 690 6416 419 >20.5
uvm2 665 6211 439 >21.4
uvw2 616 11762 1339 >20.3
----------------------------------------------
The quoted upper limits have not been corrected for the expected
Galactic extinction corresponding to a reddening of E_{B-V} = 0.015
in the direction of the XRT position (Schlegel, et al. 1998, ApJS,
500, 525). All photometry is on the UVOT photometry system described
in Poole et al. (2008, MNRAS, 383, 627).