To:   P60 group
From: Kulkarni & Cenko
Subj: Pointing Tests on P60

On June 16, 2003 (UT) we observed bright stars with P60/CCD13.
We observed a number of stars with low declinations to high
declinations on the meridian and then a similar pattern
at HA=1, 2, 3, 4, 5 and HA=-1, -2, -3, -4 and -5. We derived
pointing corrections from the observations. The radial 
rms error is 11 arcsec (after using the new pointing model).

In detail, we used 2x2 binning. (CAMERAS).
 
The image which appears on the Oscar screen
has North to the top and East to the left. The
pixel scale is 0.367 arcsec (without binning).

We TX'd overhead and then determined from the CCD
image the offset to place the star at 512, 512.
These offsets were used by John Henning to determine
a new pointing model. 

Second we checked whether the pixel position of a star
changes with focus. We concluded that there is less than
5 arcsecond displacement with 40 units of focus (1 unit
of focus = 0.066 mm). Note that under standard seeing
conditions the focus can be determined to 10 units.