[AAVSO-HEN] GRB 070508: Optical observation limiting magnitude

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
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TITLE:   GCN CIRCULAR
NUMBER:  6387
SUBJECT: GRB 070508: Optical observation limiting magnitude
DATE:    07/05/08 09:56:54 GMT
FROM:    Alan Gilmore at U of Canterbury,Mt John Obs  <alan.gilmore at canterbury.ac.nz>

A. C. Gilmore and P. M. Kilmartin (Mt John Observatory of the University of 
Canterbury) report:

We stacked 20 x 120 second clear exposures of the GRB 070508 taken with a SBIG 
ST9e CCD on a 0.6 m f/6.4 reflector at Mt John Observatory. The exposure set was 
centred on May 8 07:49 UT (3.5 hours after the burst).  Our images do not show 
any object at the coordinates given by Berger (GCN 6386) to a limiting R 
magnitude of approximately 20.5 based on USNO B1.0 stars.

These observations were made as part of the AAVSO GRB Network, and supported by 
a grant from the Curry Foundation.