GCN Circular 10730
Subject
GRB100508A: Swift/UVOT Detection of the Afterglow
Date
2010-05-08T12:20:29Z (14 years ago)
From
Wayne Landsman at GSFC/SSAI <wayne.b.landsman@nasa.gov>
W.B. Landsman (GSFC) and R. Margutti (INAF-OAB) report on behalf of the
Swift/UVOT team.
Swift/UVOT began settled observations of the field of GRB 100508A
starting 152 s after the BAT trigger (Margutti et al. GCN Circ. 10728).
An uncatalogued fading source is seen in the 2.7' x 2.7' rapidly
available subimage within the XRT error circle at
RA(J2000) = 05h 04m 58.99s
Dec(J2000) = -20d 42' 41.1"
with an uncertainty of about 0.6 arc sec (radius, 90% containment),
The initial estimated magnitudes are as follows:
Filter T_start Exp(s) Mag Err
----------------------------------------------
white 152 150 18.87 0.09
u 310 250 19.25 0.20
white 864 150 20.7 0.44
----------------------------------------------
The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.87 (Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383, 627).