[vsnet-grb-info 6023] GRB080430: Swift/UVOT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7660
SUBJECT: GRB080430: Swift/UVOT observations
DATE:    08/05/01 21:49:40 GMT
FROM:    Wayne Landsman at GSFC/SSAI  <wayne.b.landsman at nasa.gov>

W.B. Landsman (NASA/GSFC) and C. Guidorzi (INAF-OAB)  report on behalf 
of the Swift/UVOT team

The Swift/UVOT observed the field of GRB 080430 starting at 58s after  
the BAT trigger (Guidorzi et al., GCN 7647). We detect the afterglow in 
all seven UVOT filters at the position

RA(J2000.0)  =   11:01:14.66
DEC(J2000.0) =  +51:41:08.4

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).  
This position is consistent with the enhanced XRT position (Guidorzi et 
al. GCN 7653)
and the position reported from  BOOTES obervations by Jelinek et al.  
(GCN 7648).     The detection in the UVW2 (1950 A) filter is consistent 
with the
redshift of ~0.76 determined from spectroscopic observations by Deugarte 
Postigo et al. (GCN 7650) and  Cucchiara & Fox (GCN 7654). The temporal 
slope in the white filter out to 30400 seconds is approximately alpha = 
0.23.

UVOT photometry from early individual images is reported below.     

Filter    Tmid(s)     Expo(s)            Magnitude
-----------------------------------------------------
White      108          98              17.08 ± 0.03
White      928          98              18.23 ± 0.05
v          364         393              17.64 ± 0.06
v         1184         393              18.50 ± 0.09
b         5989         197              20.05 ± 0.21
u         5784         197              18.92 ± 0.12
w1        7014         197              18.89 ± 0.16
m2        6809         197              18.88 ± 0.22
w2        5684         197              19.24 ± 0.20
-----------------------------------------------------

These magnitudes are not corrected for the Galactic extinction  
corresponding to a reddening of E{B-V} = 0.012 mag (Schlegel et al. 
1998).  The photometry is on the UVOT flight system described in Poole 
et al. (2008,MNRAS,383,627).