[vsnet-grb-info 8744] GRB091127: Continuing Swift/UVOT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10245
SUBJECT: GRB091127: Continuing Swift/UVOT Observations
DATE:    09/12/04 14:27:58 GMT
FROM:    Frank Marshall at GSFC  <marshall at milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and E. Troja (NASA/GSFC/ORAU) report on  
behalf of the Swift/UVOT team:

After a relatively flat initial decay, the light curve of
the optical afterglow of GRB 091127 (Smith et al. GCN Circ. 10192;
Immler & Troja, GCN Circ. 10193) has steepened to a
decay index of 1.44 in UVOT observations with the white filter.
At 5.2 days after the BAT trigger (Troja et al., GCN Circ. 10191),
the white magnitude is 21.8 +/- 0.1.
Similar light curves are seen for the UVOT V and U filters.
The current decay index is close to that reported
by Haislip et al. (GCN Circ. 10230) using observations
between 25 and 77 hours after the trigger, and by
Cobb (GCN Circ. 10244) using data from 27.8 to 100.8
hours after the trigger.

UVOT observations of the afterglow are continuing.