Re: News from Rochester

[Tom Droege <tdroege2@earthlink.net>]

Michael,

I have been planning to point TOM2 at the equator, and TOM3 at +3.5 or 
so.  That way we can compare TOM2 data to MICHAEL and also compare all the 
TOM1 data through TOM3.

I am busy now trying a flat field without a light leak.  There was not a 
lot of obvious difference.

Hmmmm!  I guess I should run up now and start up TOM2 pointing at the 
equator and get flat fields later.  Sigh!  I just don't have the 
energy.  You have a lack of available time.  I lack energy to drag my tired 
bones around the telescopes.  OK, I know the theory about automated 
telescopes, but there always seems to be a reason to climb up into the dome 
and do something. Sigh!

Tom Droege

At 10:59 PM 9/16/02 -0400, you wrote:

>   Tonight I am going to let the Mark IV run all night, sitting
>on the equator and watching the sky go past.  I get 3 to 5 measurements
>of each star over a period of 15-25 minutes.  There are bound to be
>lots of stars with good photometry (Landolt, etc.) on the standard
>system.  I'm going to see how well I can calibrate the cameras.
>
>   It's not going to be easy, because even a little layer of cloud
>will cause the photometric calibration to change from one field
>to another.  One test I plan to make is to reduce the data in two
>ways:
>
>          a) one field at a time, differentially against Tycho stars
>                  (using Bt and Vt converted to V, I)
>
>          b) standard all-sky photometry, using Landolt (and other)
>                  standards as they occur
>
>
>   I'll probably learn something about the system by comparing the
>results of these two different methods.
>
>   Hmm.  Since I'm looking at the equator, I suppose I can _also_
>try reducing the data against the Mark III "tenxcat" magnitudes.
>Those were calibrated directly against Landolt stars, too.  Yes,
>using Landolt stars alone would be better .... if the skies here
>were clear.  But if the skies _aren't_ clear, a field-by-field
>approach may be better.
>
>   In any case, that will be my plan for the next while.  I have
>a heavy teaching load this quarter, so I won't be able to gather
>nearly as much data as Tom, nor reduce that which I gather so
>promptly.  I'll just do what I can to see how well we can
>address the concerns that Brian mentioned.
>
>                                            Michael