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    Re: Alnair identification
    From: Peter Blaskett
    Date: 2023 Nov 19, 22:51 -0800


    as asked, data is as follows :

    PA Zet Cap       64.55 degrees

    Altitudes, including Dip & Refraction

     Peacock    16d 49'

    Alnair           33d 57'

    The Zet Cap altutude of 28d 22' previously given is corrected altitude ( clear of dip & refn )

    NOTE :   these results are only given to nearest 1' of angle because of several factors.

    1.     the picture scale gives a resolution of a little over 2' af angle per pixel in the centre

    2.     the lens distortion I estimate to reach about 6 pixels in the extremities, but the pattern is not known

    3.     the Dip used is 3'.   See the Suwarrow beach picture shows the island is maybe 5 ft above high water

            and the star picture was likely taken on a tripod or table for steadiness for long exposure, so perhaps 10 ft above S/L

    It is good luck that Peacock is at the centre if the star picture. If it was not, the PA's calculated would have unknown


    Over to you then.


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