Eratta Data Set 19

[Tom Droege <tdroege@veriomail.com>]

Most of you should have Data Set 19.  There is an error in the notes as to 
what is on the Flat run, DS191.

This run has the following sequence:
1 Bias (About 2 seconds)
1 Dark (100 second)
7 Object (100 second)
1 Dark
7 Object
1 Dark
7 Object
1 Dark
1 Object

For a total of 27 frames.

For the frames, the telescope is fast forwarded for 5 seconds between each 
frame.  This causes the telescope to track the same range of sky 
(approximately) as on the following runs were it follows the sky.  The 
stars are in different positions on each frame so that the frames can be 
median combined for a flat field.  I have done this and it looks pretty 
good to me.  It is even pretty good when the flat field is used for a 
different night.  By "pretty good" I mean that the flat field is about as 
good as the noise.

Tom Droege