[vsnet-grb-info 2165] GRB050916: Swift/UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4004
SUBJECT: GRB050916: Swift/UVOT Upper Limits
DATE:    05/09/19 19:28:00 GMT
FROM:    Peter Brown at PSU  <pbrown at astro.psu.edu>

GRB050916: Swift/UVOT Upper Limits

P. J. Brown (PSU), D. Morris (PSU),  H. Huckle (UCL-MSSL),
B. Hancock (UCL-MSSL), and N. Gehrels (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began observing the field of GRB 050916
(Swift Trigger #155408) on 2005/09/16 at 16:39:20 UT,
207 seconds after the BAT trigger (Morris et al. GCN 3991).
No source is detected within the XRT error circle
(Morris et al. GCN 3996) in the initial 100 second V-band image
down to a 5-sigma upper limit of 17.9, or in summed exposures
in any of the UVOT filters down to the following 5-sigma upper limits:

Filter  T_range (s)     Exp (s)  5sigma UL

V       207 - 74,597     4455     19.9
B       353 - 65,371     4374     20.7
U       339 - 63,016     4207     20.4
UVW1    325 - 58,536     4152     20.1
UVM2    311 - 53,803     4223     20.0
UVW2    368 - 69,038     3706     20.2

The magnitudes are uncorrected for extinction,
which is extremely high as this direction lies in the galactic plane.