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    Re: Calculate GHA Aries/Some updates for web apps
    From: Sean C
    Date: 2021 Mar 4, 18:43 -0800

    Joshua,

    You wrote:

    "I am curious about how you went about making your Polaris tables.  I have read through the Astronomical Almanac and the Explanitory Supplement but it just dif not 'click' in my head well enough to construct long term tables."

    The table I made is not really "long-term". It's just an updated version of table 6 in Pub 249. It should be usable for at least a few years, though.

    I made it by using my spreadsheet to calculate the altitude of Polaris at a given location (45°N, 0°E - to be exact) and the GHA of Aries for each minute of January 1st, 2021. Then, I simply subtracted the latitude from the altitude and reversed the sign. Since the longitude is 0°, the GHA of Aries is also the LHA.

    I have attached the table below. I will probably recalculate it for some date in the future before I am done. That way, it should be usable for a bit longer.

    Cheers!

    Sean C.

    File:
    PolarisCorrection2021.pdf
       
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