GCN Circular 1433
Subject
GRB 020531, INT+WFC deep optical upper limits
Event
Date
2002-06-19T21:08:00Z (23 years ago)
From
Evert Rol at U.Amsterdam <evert@science.uva.nl>
Isabel Salamanca, Evert Rol (University of Amsterdam), Nial Tanvir
(University of Hertfordshire), Lex Kaper (UoA), on behalf of a larger
collaboration, report:
"We have observed the error box of GRB 020531 (GCN #1399, #1402) with
the Wide Field Camera on the 2.5m Isaac Newton Telescope, La Palma. The
observations were performed in Harris V filter*, under non-photometric
conditions. The field was calibrated with the calibration provided by
Henden (GCN #1422). The results are summarized below:
mid-exposure exposure time lim. magn. seeing
(UT days) (min) (3 sigma) (arcsec)
May 31.92 30 24.7 1.4
June 2.99 40 25.2 1.2
We do not measure any source fading by more than 0.3 magnitude between
the two epochs.
A refined analysis of the Chandra sources (GCN #1415, #1426) visible
in our images is being carried out and will be published in a
following GCN Circular.
An image including the IPN errorbox can be found at
http://www.astro.uva.nl/~evert/grb020531/.
We acknowledge the assistance of the ING staff."
This message can be cited.
*) The Harris V filter is close to the standard Landolt V filter. For
the calibration, color correction terms have been used and can be
found at http://www.ast.cam.ac.uk/~wfcsur/photom.html.
[GCN OPS NOTE (19Jun02): This Circular was delayed 1.5 hours
because of an obselete address in the vetted list.]