[vsnet-grb-info 6364] GRB 080714: Swift/UVOT Detection of an Optical Afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7982
SUBJECT: GRB 080714: Swift/UVOT Detection of an Optical Afterglow
DATE:    08/07/15 16:06:40 GMT
FROM:    Frank Marshall at GSFC  <marshall at milkyway.gsfc.nasa.gov>

F.E. Marshall (NASA/GSFC) and M. Perri (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080714 starting 90 s after
the BAT trigger (Perri et al., GCN Circ. 7978).  The burst is in
a crowded field only 2.5 degrees from the Galactic Plane. 
We find a fading source inside the enhanced XRT error circle 
(Goad et al., GCN Circ. 7980) in observations with the White and 
V filters. The preliminary position for the afterglow is:

  RA(J2000)  =  12:32:25.44 = 188.1060
  DEC(J2000) = -60:16:40.4  = -60.2779

with a 90% confidence error radius of about 0.8 arcsec.

The measured magnitudes in the UVOT photometric system (Poole et al.
2008, MNRAS, 383, 627) and 3-sigma upper limits for detecting
a source in the first two finding chart (FC) exposures and 
subsequent co-added exposures are:

Filter          T_start(s)   T_stop(s)      Exp(s)       Mag 

white (FC)          90          189           98         20.2 +/- 0.2
white             4290         4489          197        >20.7
v (FC)             197          596          393         19.1 +/- 0.2
v                 5896         6095          197        >19.7
b                  677         4284          206        >20.2
u                  652        12382         1137        >20.7
uvw1               628         6505          236        >19.7
uvm2               602         6300          236        >19.9
uvw2               707        16498         1007        >20.8

The values quoted above are not corrected for the predicted large, but uncertain,
Galactic extinction the direction of the burst (Schlegel et al. 1998).