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    Lunars: the tenth star
    From: Frank Reed CT
    Date: 2006 Apr 23, 22:28 EDT

    J Kalivoda, you wrote:
    "These details are  VERY important"
    
    :-) Importance is a relative thing. I'm sure you agree,  that these little
    things are important to us lunars addicts. I have finally,  just this evening,
    gotten over my "WrapPDF" addiction. I don't think I could  have typed "1-50",
    "51-100" many more times without going mad.
    
    So here's  a miniscule detail that the ECCO collection you pointed us to has
    finally  resolved for me; when did the "tenth lunars star" expire?
    
    The tenth  lunars star was Beta Capricorni, as you may recall (I brought this
    up on the  list a few years ago). For about a decade in the 18th century,
    starting with the  very first edition in 1767, lunar distances were included in
    the Nautical  Almanac for this star along with the usual nine (that list of
    nine lasted for  well over a century). Pre-computed geocentric LDs were available
    for Beta Cap  from March through December usually. Since Beta Cap is faint,
    these distances  are more or less useless in practice, and their days in the
    almanac were  numbered.
    
    I would have supposed that LDs for Beta Cap would end with  some specific
    year of the Nautical Almanac. In fact, they were dropped from the  summer months
    of the Nautical Almanac for 1777 and then dropped for good  starting in the
    almanac pages for August of 1778 (the last day with a Beta  Capricorni LD was
    July 15, 1778 --how's that for trivia). This pattern makes at  least a little
    sense because both these almanacs were being computed  simultaneously to some
    extent. The one for 1777 was completed in January, 1776  and the one for 1778
    was finished in June, 1776. So the order, probably from  Maskelyne himself, to
    stop computing distances for Beta Cap must have been given  sometime during the
    latter half of 1775 leaving the summer months of 1777  unfinished as well as
    the second half of 1778. Since these distances were almost  certainly useless
    in practice, there would have been no good reason to finish  them out for the
    year.
    
    -FER
    42.0N 87.7W, or 41.4N  72.1W.
    www.HistoricalAtlas.com/lunars
    
    
    

       
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