[vsnet-grb-info 5402] GRB 071112C: Swift/UVOT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7080
SUBJECT: GRB 071112C: Swift/UVOT observations
DATE:    07/11/13 15:29:24 GMT
FROM:    Samantha Oates at MSSL  <sro at mssl.ucl.ac.uk>

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

The Swift/UVOT observed the burst GRB 071121C (Perri et al., GCN Circ.
7059) starting with the finding chart exposure in white, 92 seconds
after the BAT trigger. The afterglow is detected at the UVOT position
given in Perri et al. (GCN Circ. 7059) in white, v, b,
u and uvw1. The afterglow decreases with an estimated temporal slope in 
the v filter of alpha =1.28.

The UVOT magnitudes and upper limits from single exposures or
co-added exposures are given below:

Filter  Tstart(s)  Tstop(s)  Exp(s)  Mag
----------------------------------------------
white     92      192         98    17.39 +/- 0.03
           859     958         98    19.0  +/- 0.1
v         198     597         393   17.9  +/- 0.4
           965     1364        393   19.3  +/- 0.3
b         679     689         10    18.3  +/- 0.4
           1444    1626        39    19.7  +/- 0.5  (2.0-sigma)
u         654     674         19    17.8  +/- 0.3
           1419    1601        39    19.3  +/- 0.5  (2.0-sigma)
uvw1      630     649         19    17.7  +/- 0.3
           1394    1576        39    19.0  +/- 0.5  (2.3-sigma)
uvm2      605     1552        78    >20.5
uvw2      708     1663        55    >20.6
----------------------------------------------

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.119 mag in the
direction of the burst (Schlegel et al. 1998).