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    Ex-Meridian Tables....Hansen vs. Norie's
    From: Doug MacPherson
    Date: 2012 Dec 24, 13:02 -0800

    Having just obtained 1915 copy of Hansen's, I have been playing around with simulated Ex-Meridian's using stars at civil twilight......set my Weems & plant Star Finder to the correct settings, and read off any stars that are within 10 to 15 degrees of 180 or 0 degrees. Compute simulated Hc etc. with online tool.

    I have noticed that I keep reaching the tables in Norie's because:

    1. the stars declination is out of range for Hansen.
    2. the star is at lower transit, Hansen does not appear to have a way of dealing with lower transits...(by the way make sure to subtact the "reduction"...learned that one the hard way).


    Norie's appears to be superior in a number of area's....Declination from 0 t0 63 degrees. Latitude from 0 to 83 degrees. Hour angles to 16 degrees (a little over one hour on either side of the meridian) with more available with table 3. Only takes up 16 pages.

    Hansen's: 0 to 30 declination, 0 to 60 lat, about one hour on either side of the meridian, 171 pages.

    My copy of Norie's is from 1991.

    Hansen's appears to have been primarily for the sun...yes? with declination centered from 0 to 23.

    Was Norie's developed later and represent an improvement?

    Thought?

    Have a great Holiday.

    Doug
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