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    Re: Lunars
    From: Bill B
    Date: 2005 Dec 10, 23:38 -0500

    > Bill, you wrote:
    > " I did not try changing  temperatures but will do.  I did occur
    > to me with Venus relatively low  in the sky and high PB refraction could be
    > playing with me."
    >
    > By the  way, I'm not suggesting that this will eliminate your errors (they're
    > insignificantly small anyway), but simply that it's interesting to see how
    > much  a temperature change of a few degrees at low altitudes *might* change
    > the results of the clearing process.
    >
    > -FER
    
    Looks like I was pretty close to a rounding point.  Using one shot with a
    -0.1 error, 2d F increase brought me from -0.1' to -0.2' error.  It took a
    10d F drop to go from -0.1' to -0.2' error.
    
    As the shots were done between 6:35 and 6:45 EST, and temp was 11d at 6:00
    and dropping, I can be sure that it was at least that cold when I did the
    observations.  Think it bottomed out at about 4d F.
    
    I was surprised that both an increase and decrease of temperature increased
    the bodies separation by 0.1'  Simplistically, I would have thought that an
    increase in temperature (BP constant) would reduce refraction and lift the
    bodies less, hence a greater observed separation.  A decrease in temperature
    would increase refraction, lifting the bodies more, and observed separation
    would be less.  Back to the think tank on that subject.
    
    If I had a strong suit, refraction would not be it. I have no clue as to how
    pressure and temperature around St. Louis (maybe lower BP, higher temp?)
    might affect the outcome.  Could it lift the lower body (Venus) less than
    predicted by local conditions, increasing the apparent separation as
    calculated from local conditions?  No idea.
    
    Bill
    
    
    

       
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