GCN Circular 8567
Subject
GRB 081127: Swift/UVOT Upper Limits
Event
Date
2008-11-27T18:03:49Z (18 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
S. T. Holland (CRESST/GSFC/USRA) and J. Mao (INAF-OAB) report on the
behalf of the Swift UVOT team:
The Swift/UVOT observed the field of GRB 081127 starting 113 s
after the BAT trigger (Mao, et al. 2008, GCN Circ. 8560). Settled
exposures started at T+131 s. We do not find any new source, relative
to the DSS or 2MASS, or any variable source inside the UVOT-enhanced
XRT error circle (Beardmore, et al. 2008, GCN Circ. 8565).
Preliminary 3-sigma upper limits for detecting a source in the white
finding chart, and the co-added images, using a 2.5 arcsecond radius
circular aperture, are
Filter T_start T_stop Exp(s) Mag
------------------------------------------
white 130 380 147 >21.3
v 365 18,799 1473 >21.0
b 466 7263 568 >21.4
u 440 13,713 1246 >21.4
uvw1 415 13,011 1276 >21.6
uvm2 389 19,496 2004 >21.8
uvw2 341 17,885 1473 >21.8
white 490 7468 714 >22.2
------------------------------------------
The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.09 mag (Schlegel, et al., 1998, ApJS, 500,
525). All photometry is on the UVOT photometry system described in
Poole et al. (2008, MNRAS, 383, 627).
The B = 13.15 mag USNO-B1.0 star 0968-0627697 is located
approximately 4 arcsec north of the XRT position. UVOT photometry at
the location of the X-ray source is contaminated by this star.