TOM2

[Tom Droege <tdroege@veriomail.com>]

Slowly I am getting TOM2 running.

While the change of lens back to the old chipped elements greatly reduced 
"ring around bright stars" problem, I now see that it did not cure it 
completely.  I can really see nothing wrong with the lenses.

I put a long lens shield on the I camera and this seemed to help the "ring" 
problem a little.  Still, I can see rings around the bright stars with TOM2 
and they are not visible on TOM1.

If anything, TOM2 is in a better position with respect to reflected light 
than TOM1.  There is nothing above TOM2.  It is in the top of the dome and 
looks down in all directions.  TOM1 sits sticking out over a porch and has 
white reflecting doors on each side.  It also sees light reflecting off the 
shed roof that houses the dome.  So I would think that TOM1 is in a worse 
situation for reflected light.

These rings have persisted for several different lenses and several cameras.

The bright star rings thus remain a mystery for TOM2.

I spent some time moving TOM2 around to get it aligned to north.  The way I 
do it is to use "follow" fields and measure star movement on successive 
fields.  I can then rotate the dome platform for N-S drift and adjust the 
RA DAC for E-W drift.  They do not affect each other very much.

TOM1 continues to take pretty good looking data (to me).  I collected 56 
images in V and I each for five different fields last night.  Unusual 
weather for December when the moon is dark, but I am enjoying it and 
getting a lot of images on disk.   As I recall, last year I never got a run 
that was even close to the longest night of the year.  This year I have 
several.

Tom Droege