[vsnet-grb-info 2885] GRB 060206: Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4722
SUBJECT: GRB 060206: Swift/UVOT Observations
DATE:    06/02/09 22:27:58 GMT
FROM:    Padi Boyd at GSFC  <padi at milkyway.gsfc.nasa.gov>

P. Boyd (GSFC), D. Morris (PSU), F. Marshall (GSFC), N. Gehrels (GSFC)
on behalf of the Swift/UVOT team report:

The Swift/UVOT began observing the bright afterglow of GRB 060206 at
04:47:52 UT on 2006-02-06, approximately 57s after the BAT trigger (Morris
et al., GCN 4682). The afterglow is well detected in the individual B and
V exposures during the initial observation. The afterglow re-brightens in
both filters between 2000 to 5000-s after the BAT trigger. After this
event, the flux decays in both filters with a slope of ~1.15.

Filter          T_range(s)      Exp(s)  Average mag
V                57-36588       2618     18.8 
B               1662-34946      2911     21.3 

Reported times are in seconds since BAT trigger.

In a follow-up observation, beginning about 0.8 d after the BAT trigger,
the source is not detected in B nor V down to the following 3-sigma
magnitude upper limits:

Filter          T_range(s)      Exp(s)  mag upper limit
V               69308-150688    5001     >21.7
B               69656-150353    4679     >22.6

The afterglow is not detected in any other UVOT filter down to the
following 3-sigma magnitude upper limits:

Filter          T_range(s)      Exp(s)   mag
U               1637-23385      1161    >21.5
UVW1            1757-5619       256     >20.6
UVM2            1733-30466      514     >21.3 
UVW2            1686-35861      2638    >22.7

These magnitudes are uncorrected for Galactic extinction;
E(B-V) = 0.013.