Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 9899

Subject
GRB 090904A: Swift/UVOT Refined Analysis
Date
2009-09-05T05:46:33Z (15 years ago)
From
Tyler Pritchard at PSU <tapritchard@astro.psu.edu>
T. A. Pritchard (PSU), C. A. Swenson (PSU) and M. Perri (ASDC) report on 
behalf of the
Swift/UVOT team:

The Swift/UVOT began settled observations of GRB 090904A,  141 seconds 
after the
BAT trigger (M. Perri et al., GCN Circ. 9879). We do not detect any 
source at the
UVOT-enhanced XRT position (M.R. Goad, GCN Circ. 9885).

The 3-sigma upper limits for the exposures are:

Filter   T_start(s)   T_stop(s)   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white      141      	1189       341      > 21.57
v          629       	1078        58      > 18.72
b          555          1177        58      > 19.59
u          299       	1152       285      > 20.43
uvw1	   679		1127	    58      > 19.11
uvm2	   827		847	    19      > 17.61
uvw2	   605		1054	    58      > 19.17
-------------------------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction corresponding to a reddeningalong the line of sight of
E_(B-V) = 0.1 mag (Schlegel et al., 1998, ApJS, 500, 525).  All 
photometry is on the
UVOT photometric system described in Poole et  al. (2008, MNRAS, 383, 627).
Looking for U.S. government information and services? Visit USA.gov