GCN Circular 3123
Subject
GRB 050318: SWIFT-UVOT refined analysis
Date
2005-03-19T22:42:15Z (19 years ago)
From
Martin Still at NASA/GSFC Swift SSC <Martin.Still@gsfc.nasa.gov>
M. De Pasquale (MSSL), P. Boyd (GSFC/UMBC), S. T. Holland, M. Still
(GSFC/USRA), W. Landsman (GSFC), S. Hunsberger (PSU), A. Breeveld
(MSSL), P. Roming (PSU), K. Mason, P. Schady (MSSL), M. Ivanushkina
(PSU), T. Poole (MSSL), C. Gronwall (PSU), A. Blustin (MSSL), P. Brown
(PSU), S. Rosen, K. McGowan (MSSL), S. Koch (PSU), M. Carter, H. Huckle
(MSSL), P. Broos (PSU), T. Kennedy, P. Smith, B. Hancock (MSSL), H.
Krimm (GSFC/USRA), J. Nousek (PSU), N. Gehrels (GSFC), on behalf of the
Swift UVOT team.
Analysis of a more complete data set from the Swift-UVOT
of GRB 050318 (Krimm, et al., GCN 3111) yields an
improved position from stacked V image exposures of
RA = 03h 18m 51.15(2)s, Dec = -46d 23m 43.7(3)s (J2000).
Images in various filters, stacked over the first 34
ksec after the trigger indicate time-averaged
instrumental magnitudes of UVW2 > 22.0, UVM2 > 22.1,
UVW1 > 21.5, U = 20.5(2), B = 20.0(1) and V = 19.7(1).
This indicates either a highly reddened source, or an
object of redshift z ~ 2.7 in front of the burst.
Magnitudes are based on ground calibration and will
require confirmation in flight.