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    Re: Sun sights during an eclipse: "bad limb" calculation
    From: Geoff Hitchcox
    Date: 2023 Oct 11, 02:37 -0700

    Frank wrote:

    > 17:07:46, but you go ahead and shoot that sharp point at the lower edge

    > of the Sun as if it is still the LL thirty seconds later, how wrong would that be?

    Using JPL Ephemeris - No Refraction

    2023-Oct-14 17:07:46 -> 52.340606 degrees = Elev of Suns LL

    2023-Oct-14 17:08:16 -> 52.370177 degrees = Elev of Suns LL

    30 second Delta = 0.029571 degrees = 1' 46.456" in LL elevation.

    Frank wrote:

    > How wrong could you be on the time and incur less than 0.1'

    > error in the Sun LL altitude? Or how about 0.5' error?

    At time of initial obscuration:

    0.1' change in LL Elev is about 2.0 seconds of time.

    0.5' change in LL Elev is about 9.5 seconds of time.

    Lars, thank you for your comments, nice to know we agree!

    Now for some more fun, playing with code.

    If one was lucky enough to be near the Sundial (in front of the Treworgy Planetarium) on Saturday (14 Oct 2023) - when would the eclipse occur?

    Assumed location is = N 41.36198 W 71.96390
    (Following times are UT)
    2023-Oct-14 16:15:10.5 = First contact Moon has with Sun.
    2023-Oct-14 17:11:41.5 = First contact Moon has with SunLL.
    2023-Oct-14 18:22:06.5 = Last contact Moon has with SunLL.
    2023-Oct-14 18:35:45.5 = Last contact Moon has with Sun.
    Regards, Geoff Hitchcox, Christchurch, New Zealand.
       
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