[vsnet-grb-info 6645] GRB080916A: Refined Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8249
SUBJECT: GRB080916A: Refined Swift/UVOT Observations
DATE:    08/09/16 19:58:10 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

S. R. Oates (UCL-MSSL) and H. Ziaeepour (UCL-MSSL) report on
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 080916A, 78s after the BAT trigger (Ziaeepour et al., GCN 8237).
We detect the afterglow in all of the UVOT filters at the position:

RA(J2000.0)  =  22:25:06.20
DEC(J2000.0) =  -57:01:22.9

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).
This position is consistent with the UVOT enhanced XRT position (Evans et
al., GCN 8241) and the REM position (Fugazza et al., GCN 8238).

UVOT magnitudes are reported below for the finding charts (fc) and images:

Filter    Tstart(s)  Tstop   Expo(s)   Magnitude/3sigUL
-----------------------------------------------------
white (fc)    78    178        98       18.33 +/- 0.06
white        872    972        98       18.47 +/- 0.06
v     (fc)   182    582       393       17.55 +/- 0.06
v            978   1378       393       18.39 +/- 0.11
b           1458   1477        19       18.90 +/- 0.35
u            538    658        19       17.53 +/- 0.19
w1           613    633        19       18.25 +/- 0.39
m2           741   1565        39       18.42 +/- 0.40
w2           692    864        39       18.75 +/- 0.37
-----------------------------------------------------

These magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E{B-V} = 0.02 mag (Schlegel et al.
1998). The photometry is on the UVOT flight system described in Poole
et al. (2008,MNRAS,383,627).