[vsnet-grb-info 4055] GRB 061126: Early Super-LOTIS Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5869
SUBJECT: GRB 061126: Early Super-LOTIS Observations
DATE:    06/11/27 04:21:25 GMT
FROM:    Grant Williams at Steward Observatory  <ggwilli at mmto.org>

G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of 
the Super-LOTIS Collaboration, report:

The robotic 0.6-m Super-LOTIS telescope began observing the error box of 
GRB 061126 (Swift Trigger 240766, Sbarufatti et al. GCN 5854) at 
08:48:30.7 UT, 35 seconds after the trigger.  Our initial observations 
include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all 
in the R-band.

Observations were hampered by high winds; most of the images are elongated 
as a result of wind buffeting.  Despite the poor image quality we clearly 
detect the bright optical afterglow first reported by Vanden Berk (GCN 
5856) in all our early images.

Using the single USNO-B1.0 star at RA=05:46:31.61, Dec=+64:11:59.7 with 
R2MAG=12.80, we estimate the following R-band magnitude for the OT using 
circular aperture photometry (despite elongated images):

t_start (UT)	exp t (s)	t_start-t_0 (s)	R Mag
----------------------------------------------------------------
08:48:30.7	10.0 		35 		R = 12.93 +/- 0.2

Because of the elongated PSF the error bar is a conservative estimate. 
Continued analysis is underway.