TITLE:   GCN CIRCULAR
NUMBER:  14069
SUBJECT: GRB121212A: Swift/UVOT Detection
DATE:    12/12/12 17:14:59 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N.P.M. Kuin (MSSL-UCL) and D. Grupe (PSU) report on behalf
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121212A
72 s after the BAT trigger (Grupe et al., GCN Circ. 14064).  A source
consistent with the enhanced XRT position (Beardmore et al. GCN Circ.
14066) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  11:51:10.30 = 177.79292 (deg.)
   Dec (J2000) = +78:02:14.3  =  78.03730 (deg.)
with an estimated uncertainty of 0.62 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early
exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               72         7133          824         21.23 +/- 0.17
v                  615         6108          352        >20.3
b                  540        13527         1160        >20.9
u                  285         1138          285         20.25 +/- 0.25
w1                 664        11960         1238        >20.8
m2                 639         6313          216        >20.5
w2                 763         5904          255        >20.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).