GCN Circular 10508
Subject
GRB 100316B: Swift/UVOT observations
Event
Date
2010-03-16T19:29:42Z (16 years ago)
From
Patricia Schady at MSSL/Swift <msslba@googlemail.com>
S. R. Oates (MSSL-UCL) and W. H. Baumgartner (GSFC/UMBC) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began observerving the field of GRB 100316B 67s
after the BAT trigger (Baumgartner et al., GCN Circ. 10489). We detect the
optical afterglow in the white, v, b, u and marginally in the uvw1 filter.
The refined UVOT position is RA (J2000)= 163.48809, DEC (J2000)=-45.47265,
which is equivalent to:
RA (J2000) = 10:53:57.141
Dec (J2000) = -45:28:21.54
with an estimated uncertainty of 0.52 arcsec (radius, 90% confidence).
This position is consistent with the XRT refined position (Beardmore
et al., GCN Circ 10502). The marginal detection in the uvw1 filter is
consistent with
the VLT redshift upper limit (D'Avanzo et al., GCN Circ. 10495).
Preliminary magnitudes and the 3 sigma upper limits are reported below for
individual optical images and summed UV images.
Filter T_start(s) T_stop(s) Exposure Mag Err
###########################################################
white 67 216 147 18.36 +/- 0.05
white 857 1007 147 19.15 +/- 0.09
u 279 528 246 18.44 +/- 0.10
v 1212 1232 19 18.28 +/- 0.46
b 535 555 19 18.97 +/- 0.36
uvw1 659 1108 58 18.91 +/- 0.36
uvm2 634 1246 66 > 18.59
uvw2 585 1207 78 > 19.13
###########################################################
The above magnitudes are not corrected for the Galactic extinction
corresponding to a non-negligible reddening of E_{B-V} = 0.14 mag
(Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383,627).