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    Re: Lewis and Clark lunars
    From: Ken Muldrew
    Date: 2004 Apr 23, 16:18 -0600

    On 23 Apr 2004 at 17:31, Fred Hebard wrote:
    
    > A one-day error would come close to 15 degrees.
    
    But the moon would almost be on top of Regulus, and too close to the
    Eastern horizon to assume a mistaken star on that side.
    
    I just checked the Regulus data and found that the error for each
    measurement is between 8 and 12 minutes, with an average of 10'.
    Since it's consistently in the same direction as the 15' error for
    the Aldebaran/Betelgeuse measurements, it might be close enough to be
    convincing evidence that L&C were reading from the wrong side of the
    sextant on that night. I have probably underestimated the error
    because I haven't taken temperature into account. Since Regulus is
    pretty close to the horizon here, I wonder if the cold temperature
    could have increased the apparent distance by enough to close the
    gap.
    
    >  Do moon altitudes
    > accompany the lunar distances?  These would settle this question
    > quickly.
    
    I don't think L&C ever took moon altitudes. The astronomical notebook
    that George Huxtable has transcribed and put on the web instructs
    them in calculated altitudes, and I believe the Preston paper also
    discusses their lack of lunar altitudes. It would have been nice if
    they did, though.
    
    Ken Muldrew.
    
    
    

       
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