[vsnet-grb-info 7174] GRB 081230: Swift/UVOT Detection of an Optical Afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8755
SUBJECT: GRB 081230: Swift/UVOT Detection of an Optical Afterglow 
DATE:    08/12/30 21:21:51 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland at milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA), P. J. Brown (PSU), and V. La Parola
(INAF-IASFPA) report on the behalf of the Swift UVOT team:

        The Swift/UVOT detects a faint source in the XRT error circle
for GRB 081230 (La Parola, et al. 2008, GCN Circ. 8753).  The source
has a preliminary position of

     RA (J2000)   02:29:19.48  =   37.33117 (deg)
     Dec (J2000) -25:08:48.5   =  -25.14682 (deg)

and a preliminary u-band magnitude of u = 20.6 +/- 0.3 mag in a 250 s
exposure starting 131 s after the BAT trigger.  The quoted magnitude
has not been corrected for the expected Galactic extinction along the
line of sight corresponding to a reddening of E_{B-V} = 0.01 mag
(Schlegel, et al., 1998, ApJS, 500, 525).  The photometry is on the
UVOT flight system described in Poole et al. (2008, MNRAS, 383, 627).