[vsnet-grb-info 3596] GRB060807: Optical limiting magnitudes

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5430
SUBJECT: GRB060807: Optical limiting magnitudes
DATE:    06/08/09 18:03:12 GMT
FROM:    AAVSO GRB Network at AAVSO  <aavso at aavso.org>

D. T. Durig (Cordell-Lorenz Observatory, University of the South) and S. 
Sposetti (Gnosca, Switzerland) report on behalf of the AAVSO International 
High Energy Network on optical observations of GRB060807 (GCN #5409, De 
Pasquale et al.):

D. T. Durig reports the following unfiltered (CR) limiting magnitude:
2006 Aug 08, 03:41:45 UT, CR < 20.0 (15 hours, post-burst)

S. Sposetti reports the following R-band limiting magnitude:
2006 Aug 08, 19:45:00 UT, R < 20 (29 hours, post-burst)

Details of these observations follow at the end of this report.

FITS images of these observations are available from the AAVSO at
ftp://ftp.aavso.org/grb , and full details of these observations
are available at the following URLs:

Durig: http://www.aavso.org/pipermail/aavso-hen/2006-August/006238.html
Sposetti: http://www.aavso.org/pipermail/aavso-hen/2006-August/006240.html

The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.

--------------------------

Observer: D. T. Durig  ( CLW01 )
Report: Started 2 hours of 30 second unguided exposures and got a few
thicker clouds near the end. So I added the first 150 good frames, total
exposure 75 minutes. No OT observed, but there is a dim background
variation at S/N~2 near reported position. Two accumulated hot pixels
nearby center at 1 oclock position and one near top center of frame are
artifacts. Gif image at http://arthur.sewanee.edu/obsv/view.php
Bright moonlight made background very bad and limited depth of
coverage.

Observer: Stefano Sposetti
Report: Observations begun at 19:45UT, aug 8th, about 29h later the
Swift-BAT trigger, under good sky conditions affected by moonlight. A
90min stacked R-filtered image centred at 20:45UT doesn't show any OT
brighter than 20mag (USNO A2.0 catalog).