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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Ritchie
Date: 2025 Mar 26, 15:29 -0700
Bonjour Antoine,
In your recent post, you said "Our so dear Mr Jean Meeus aced it again here !"
Exactly so! In his Astronomical Algorithms Second Edition he lists an abbreviated table (47B) of ELM200/82 of only 30 terms to calculate the Moon's latitude. Using this to calculate the subject 2025 minimum declination gives -28° 43' 33.762" at 06:37:20.
This compares with ...
(a) his separate formula method yielding -28°43' 32" at 06:37:51 UT and
(b) Your full INPOP 2019 Result of -28°43' 32.427" at 06:37:27 UT and
(c) full ELP/MPP Lunar Theory of -28° 43' 32.472" at 06:37:27 UT.
Amazing for only a 30 term ephemeris.
I wonder if I ever met Jean. I visited Brussels airport regularly between 1964 and 1980, occasionally thereafter, and sometimes visited the met office during turnrounds.
Bill