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    Re: Alnair identification
    From: Antoine Couëtte
    Date: 2023 Nov 20, 13:15 -0800

    Dear Peter,

    Thanks for your feedback with numbers and for your Suwarrow Island picture.

    From your Zeta Cap corrected altitude at 28d 22', I am guessing that your "raw" Altitude is 28d 27'  ("raw", i.e. including Refraction and your 3' Dip).

    Our updated fine-tuned Picture environment being :

    S13°15'/W163°06.5' , on 01 Jan 2019, HoE = 9.5 ft,  T = +25°C, P=29.92 "Hg, working backwards from your feedback numbers we get :

    (1) - From Peacock - Alnair Position Angle at 20.045° , we get : Picture UT#1 = 05h56m04s

    (2) - From Peacock - Zeta Cap Position Angle at 64.55°, we get : Picture UT#2 = 05h55m43s

    (3) - From Zeta Cap corrected Altitude at 28d 22', hence Zeta Cap raw Altitude at 28°27' we get : Picture UT#3 = 05h55m36s

    (4) - From Alnair raw Altitude at 33°57' we get : Picture UT#4 = 05h55m50s

    (5) - From Peacock raw Altitude at 16°49' we get : Picture UT#5 = 05h55m41s

    which yields an average value at 05h55m47s.

    Aa a confirmation to our last provisional results, your measurements indicate that the Picture was taken at 05h56m with an error bar almost certainly inferior to 3 min and possibly inferior to 1 min,

    FINAL RESULT : Picture UT = 05h56m +/ 2 min

    (not far from earlier initial determination).

    Thanks again to you both, Frank and Peter,


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