GCN Circular 8603
Subject
Swift UVOT observations of GRB 081203A
Event
Date
2008-12-03T22:06:27Z (17 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale (MSSL/UCL) and A. Parsons (GSFC) reports, on the
behalf of the Swift UVOT team:
Swift UVOT began settled exposures of GRB081203A (trigger 336489,
Parsons et al, GCN circular 8595) 93 s after the burst trigger. A
bright optical transient is detected at the following coordinates:
RA = 15h 32m 07.58s (=233.031580), Dec = +63d 31m 14.9s (=63.520810)
J2000
with an uncertainty of 0.5'' (90% confidence level). This position is
consistent with the XRT refined error circle (Goad et al, GCN circ 8598).
The source is detected in all filters but um2. Below, we show time of
observations, the exposure time and the magnitude and 3 sigma upper
limits for this optical afterglow.
T_start (s) T_stop (s) Exp (s) Mag
wh 93 242 146.2 14.53 +/- 0.01
wh 586 605 19.5 13.91 +/- 0.01
v 636 655 19.5 13.30 +/- 0.03
b 561 580 19.5 13.53 +/- 0.01
u 306 555 246 13.07 +/- 0.01
u 709 728 19.5 13.53 +/- 0.02
uw1 685 704 19.5 14.82 +/- 0.07
um2 660 679 19.5 > 17.57
um2 660 6008 412.6 > 20.1
uw2 611 630 19.5 17.19 +/- 0.25
The nondetection in the um2 filter is consistent with the
redshift z=2.1 derived from grism spectra (Landsman et al, GCN
circ 8601). The detection in the uw2 filter is consistent with
this redshift due to the long-wavelength tail of the uw2
filter response.
The above magnitudes have not been corrected for the Galactic
extinction corresponding to E(B-V) = 0.02 (Schlegel et al 1998)
The photometry is on the UVOT flight system described in Poole
et al (2008, MNRAS, 383,627)
[GCN OPS NOTE(03dec08): Per author's request, the "A" was added to the burst name.]