GCN Circular 11482

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

The Swift/UVOT began settled observations of the field of GRB 101219B
156 s after the BAT trigger (Gelbord et al., GCN Circ. 11473
Not found
 
 
).
The optical afterglow is at 7 arcsec distance of a 16th magnitude star.
Special care has been taken to subtract the estimated contribution
of the neghboring star.  The data suggest that after an initial
brightening, there was a dimming around T+550s followed by a
second brightening.

Preliminary magnitudes of the GRB, using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and some selected subsequent exposures are:

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

white_FC           156          306        147.4       17.87   0.06
white              768          788         19.5       17.59   0.10
white             6686         6886        196.6       18.58   0.06
v                  820          840         19.5       17.55   0.27
v                 7097         7296        196.6       18.39   0.15
b                  570          590         19.5       18.79   0.30
b                  744          764         19.4       18.00   0.19
u                  718          738         19.5       17.25   0.18
u                 1298         1318         19.5       17.26   0.18
uvw1              1446         1465         19.4       17.43   0.28
uvw1             16352        16861        501         18.40   0.11
uvm2              7301         7392         89.6       18.15   0.24
uvm2             51175        52075        856         19.54   0.16
uvw2              6892         7092        197         18.04   0.13
uvw2             56901        57801        886         20.21   0.20

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).