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    Re: Lunar-distance almanac errors.
    From: Frank Reed CT
    Date: 2004 Jul 13, 17:31 EDT
    George H wrote:
    "Roughly speaking, that's ±5 arc-sec, which is compatible with my chosen rounding-off of display to 0.1 arc-min. So I don't claim any higher accuracy than that rounding.

    There are additional errors due to some simplifications. For example, I consider only the 18.6 year term in the nutation correction and ignore the rest. But that contribution to error is expected to be small."

    OK, well, in the event that you do not want to add this additional source of error (every little tenth of a minute counts!) to your historical lunars analyses, you may want to know that my online star positions are accurate to better than one arcsecond (less than 0.2 arcseconds error). I allow the Moon's position to vary from the JPL ephemerides by as much as 1 arcsecond, so predicted lunar distances are accurate to 1 arcsecond.

    Online Lunars Almanac, Online Nautical Almanac:
    http://www.HistoricalAtlas.com/lunars/

    Frank R
    [ ] Mystic, Connecticut
    [X] Chicago, Illinois
       
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