GCN Circular 10199
Subject
GRB 091127: Swift/UVOT observations
Event
Date
2009-11-28T05:17:52Z (17 years ago)
From
Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>
S. Immler (CRESST/UMCP/GSFC) and Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091127
3219 s after the BAT trigger (Troja et al., GCN Circ. 10191).
We detect the optical afterglow at the refined UVOT position
RA, Dec 36.58288, -18.95239, which is
RA (J2000) 02:26:19.89
Dec (J2000) -18:57:08.63
with an estimated uncertainty of 0.55 arcsec (radius, 90% confidence).
This position is consistent with ground-based optical/IR detections of
the afterglows (Smith et al., GCN 10192; Fugazza et al., GCN 10194;
Updike et al., GCN 10195; Xu et al., GCN 10196; Gorosabel et al.,
GCN 10198). Preliminary magnitudes are reported below.
Filter T_start(s) T_stop(s) Exposure(s) Mag Err
------------------------------------------------------------------------
white 3219 3369 147.4 16.2 +/- 0.1
v 3375 3575 196.6 17.0 +/- 0.1
uvw1 3785 5600 156.1 15.9 +/- 0.1
uvm2 3580 3780 196.6 15.6 +/- 0.1
-------------------------------------------------------------------------
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998, ApJS, 500, 525). The photometry is on the UVOT
photometric system described in Poole et al. (2008, MNRAS, 383, 627).