GCN Circular 14063

M. M. Chester (PSU) and V. Mangano (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121211A
97 s after the BAT trigger (Mangano et al., GCN Circ. 14057
Not found
 
 
).  A source
consistent with the enhanced Swift-XRT position (Osborne et al. GCN  
Circ.
14060
Not found
 
 
) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  13:02:07.99 = 195.53328 (deg.)
   Dec (J2000) = +30:08:54.6  =  30.14849 (deg.)
with an estimated uncertainty of 0.52 arc sec. (radius, 90% confidence).

The following table provides preliminary detections and 3-sigma upper
limits for the finding charts and summed exposures using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).
The lack of a detection in uvw2 is consistent with the redshift of
1.023 reported by Perley et al. (GCN Circ. 14059
Not found
 
 
).


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

white_FC            97          247          147         18.4 +/- 0.1
white             4103         5738          393         19.9 +/- 0.1
v                 4514         6148          393        >19.9
b                 3899         5533          393         20.4 +/- 0.2
u_FC               255          297           41         18.3 +/- 0.3
u                 5128         5328          197         19.6 +/- 0.2
w1               10576        11476          886         20.6 +/- 0.2
m2                4718        10569         1082         20.6 +/- 0.2
w2                4309         5943          393        >21.1

The magnitudes in the table are not corrected for the Galactic  
extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).