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    Re: Polaris SHA
    From: Paul Hirose
    Date: 2008 Sep 20, 19:24 -0700

    Here is a table of the SHA of Polaris on the first day of each month in 
    2008. The values are for 0 hours Terrestrial Time (= Terrestrial 
    Dynamical Time = Ephemeris Time). This time scale is ahead of UT1 by a 
    value called delta T, currently about 65 seconds.
    
    The left column is the month.
    The first SHA column includes precession and nutation but not
    aberration. There's a continuous decrease amounting to 22' during the year.
    The center SHA column includes aberration but not precession and
    nutation. It shows a periodic variation through a range of 53'.
    The last column includes all effects. The total variation is more than
    one degree during the year.
    
    Polaris coordinates for 2008
    01  319°46.3'  319°31.5'  319°31.5'
    02  319°44.5'  319°45.5'  319°43.7'
    03  319°43.4'  319°58.7'  319°55.8'
    04  319°42.0'  320°09.0'  320°04.8'
    05  319°40.2'  320°12.7'  320°06.7'
    06  319°37.7'  320°09.5'  320°01.0'
    07  319°35.1'  320°00.5'  319°49.5'
    08  319°33.3'  319°47.7'  319°34.8'
    09  319°32.4'  319°34.3'  319°20.4'
    10  319°31.2'  319°24.1'  319°09.0'
    11  319°29.0'  319°19.4'  319°02.0'
    12  319°26.3'  319°22.1'  319°01.9'
    01  319°23.9'  319°31.8'  319°09.2'
    
    What about parallax and proper motion? They're included in all columns
    but don't have their own column because at .1' resolution the monthly
    SHA values are identical.
    
    Basis of the tabulation: star coordinates, parallax, and proper motion
    from the Hipparcos catalog. Transformation to apparent coordinates of
    date via The Astronomical Almanac rigorous method. IAU 2006 precession,
    IAU 2000A nutation.
    
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