From: Patrick J. P. McCarthy <pmc2@ociw.edu>
To: pmc2@ociw.edu, rgm@ast.cam.ac.uk
Cc: cdm@ast.cam.ac.uk, sabbey@ast.cam.ac.uk
Subject: Re: CIRSI H zeropoint info for Nov run

Richard - Below are the zero points that
we have determined for the May and October
runs. There are a few nights that remain to
be calibrated. The number listed is the zmag
for 2x2 block replicated images, to get to the
same zmag that you sent, subtract 1.505 mags.
We find excellent stability at Hx, but fairly
large variations at Jg. I suspect that the Jg
variation is just water bands opening and closing,
but the amplitude seems larger than my previous
experience with the standard J filter.

Pat


DATE  Day       Hx       Jg
m.d    #       zmag     zmag
05.05 125      ...     22.80
05.09 129      ...     23.035
05.14 134      ...     23.070
05.17 137      ...     23.018
05.18 138     23.53    23.065
05.19 139     23.53     ...
05.20 140      ...     22.715
05.21 141      ...     22.735

10.16 289     23.62     0.0
10.20 293     23.58     0.0
10.23 296     23.56     0.0
10.24 297     23.57     0.0
10.25 298     23.53    23.08
10.26 299     23.57    23.17
10.28 301     23.58     0.00
10.29 302     23.59    23.08