GCN Circular 9177
Subject
GRB 090419: Swift/UVOT Observations
Event
Date
2009-04-20T20:31:07Z (17 years ago)
From
Michael Siegal at Swift/PSU <siegel@astro.psu.edu>
M. H. Siegel (PSU), E. A. Hoversten (PSU) and G. Stratta (ASDC) report
on behalf of the Swift/UVOT team.
The Swift/UVOT began observing the field of GRB 090419 126s after the
BAT trigger (Stratta et al., GCN Circ. 9161). Data summed over the
first
orbit reveals a very faint (3.3 sigma) source in the white filter at the
refined position of the X-ray afterglow (Osborne et al., GCN Circ.
9164).
This source is not detected in the second orbit data.
The detection and 3-sigma upper limits for the finding chart (fc) and
summed exposures are reported below:
FILTER T_start(s) T_stop Exposure Mag/3UL
=============================================================
white fc 126 276 147 > 20.69
white 126 1706 410 21.07+-0.31
white 5320 6956 393 > 21.25
v 614 1756 136 > 18.93
v 5732 7367 393 > 19.60
b 540 1682 116 > 19.87
b 5116 13394 572 > 20.69
u 284 1829 362 > 20.25
u 6346 13206 1081 > 20.89
uvw1 664 1805 136 > 19.31
uvw1 6142 12292 1118 > 20.63
uvm2 639 1608 58 > 18.41
uvm2 5936 17728 465 > 19.99
uvw2 590 1731 136 > 19.37
uvw2 5527 7162 393 > 20.13
=============================================================
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.296 (Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383, 627).