GCN Circular 11718

N.P.M. Kuin (MSSL/UCL) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110213A
100 s after the BAT trigger (D'Elia et al., GCN Circ. 11705
Not found
 
 
). This GRB
was reported by many observers. We see an initial peak around T+300s
after which the GRB declines in brightness until around T+1500s when
a small rebrightening occurs. A tentative redshift was reported by
P.A. Milne (GCN Circ. No 11708) of z=1.46, which is consistent with
the much fainter magnitudes we find in the uvm2 and uvw2 filters.

The refined uvot position (90% confidence limit, 0.5" accuracy) with
reference to USNO-B1 is:

RA  (J2000) =  02h 51m 51.39s
DEC (J2000) =  49d 16' 23.54"

Preliminary magnitudes and 3-sigma upper limits in the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627) for
the first finding chart (FC) exposures and summed with subsequent
exposures up to about 2500s are:

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

white_FC           100          250          147         16.36 +/- 0.05
u_FC               312          562          246         15.54 +/- 0.04

white              100         2579          517         16.57 +/- 0.01
v                  642         2455          227         16.19 +/- 0.04
b                  568         2206          178         16.77 +/- 0.03
u                  312         2529          448         15.94 +/- 0.02
uvw1               692         2505          198         17.28 +/- 0.08
uvm2               667         2479          218         18.72 +/- 0.20
uvw2               618         2606          238         19.10 +/- 0.18

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.32 in the direction of the burst
(Schlegel et al. 1998).