[vsnet-grb-info 5322] GRB 071025: Kuiper Telescope Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7011
SUBJECT: GRB 071025: Kuiper Telescope Optical Observations
DATE:    07/10/27 19:49:05 GMT
FROM:    Grant Williams at Steward Observatory  <ggwilli at gmail.com>

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

The 1.54m Kuiper telescope began observations of the error region of
GRB 071025 (Swift trigger 295301, Pagani et al. GCN 6986) at 04:37:08
UT, approximately 28 minutes after the trigger.  Observations were
obtained in the V, R, and I-bands. The afterglow first reported by
Rykoff et al. (GCN 6987) is clearly visible in the individual early R
and I band images but not in the V-band images or in the sum of the
V-band images.  Observations continued until 09:47:09 UT.

The aperture photometry results below were obtained from sums of
individual images using nearby stars in the USNO-B1.0 and NOMAD
catalogs. Further analysis of additional epochs is continuing.

Filter UT-Start       UT-End        exp (s) magnitude error
R ---- 04:37:08 ----- 04:41:30 ---- 150 --- 18.7 +/- 0.1
R ---- 04:42:14 ----- 05:02:40 ---- 1080 -- 19.3 +/- 0.1
R ---- 05:03:12 ----- 05:24:11 ---- 1080 -- 19.8 +/- 0.1

V ---- 05:43:38 ----- 06:07:46 ---- 1200 -- < 22.0

I ---- 05:25:05 ----- 05:42:39 ---- 960 -- 18.2 +/- 0.1
I ---- 08:01:20 ----- 08:55:41 ---- 3000 -- 19.9 +/- 0.15

This message may be cited.