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    Re: Lunars arcsecond differences
    From: Modris Fersters
    Date: 2023 May 17, 01:45 -0700

    Hello, Frank!

    Your last post (answer to mine) contains some interesting issues I will discuss in separate post under a new subject name.

    But I have some questions about software calculators:

    1) You mentioned that no one of software developers take into consideration the irregularities of the Moon’s limb (+/-3”). But does that mean , if I compare different softwares, I can ignore these irregularities (because all developers use the same average model of the limb)? Or maybe the simplified limb models differs one from other?  

    2)I found another strange thing while using your online lunar calculator. Let's use the same examples I posted before:

    * Sun-Moon near limbs; 30.04.2023; 16:20:00; Frank’s distance: 120° 28,59'
    *Capella-Moon near limb; 03.05.2023; 19:20:00; Frank’s distance: 114° 58,44'.

    I got these lunar distance values by leaving the fields blank to let the program to calculate the altitudes for given position. But if I fill the altitudes, the program calculates the distance that differs about 0,1’ (see attached pdf file). Why is there such a difference? It means that if I use filled in altitudes your calculator generates results that are close to Paul’s and Antoine’s results (difference 0,1' and 0,02' accordingly).

    Modris Fersters 

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