GCN Circular 8606
Subject
Swift/UVOT detection of GRB081203B
Date
2008-12-04T00:37:27Z (15 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL-UCL), F.E. Marshall (NASA/GSFC) and B. Sbarufatti
(INAF-IASF Pa) report on behalf of the Swift/UVOT team:
The Swift/UVOT began white band observations of the field of the Swift
BAT Slew Survey (BATSS) GRB 081203B 4.6 hrs after the BAT trigger
(Copete et al., GCN Circ. 8600, 8602). An uncatalogued, fading source
is clearly detected at
RA(J2000.0) = 15:15:11.67 (228.79863 deg)
DEC(J2000.0) = +44:25:42.9 (44.42859 deg)
with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence),
consistent with the UVOT-enhanced XRT position (Sbarufatti et al., GCN
Circ. 8605).
The magnitudes of the first and last UVOT white band observations are
reported below:
Filter T_mid (s) Exp (s) Magnitude
white 16746 154 18.29 +/- 0.04
white 22270 441 18.70 +/- 0.03
indicating a decay rate of alpha~1.0. The above magnitudes are not
corrected for the Galactic extinction corresponding to a reddening of
E_{B-V} = 0.02 mag (Schlegel et al., 1998, ApJS, 500, 525). The
photometry is on the UVOT flight system described in Poole et al.
(2008, MNRAS, 383,627).