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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Sean C
Date: 2023 Mar 20, 19:33 -0700
Using my spreadsheet, I get an apparent geocentric longitude of 359°59'59.98" at 21:24:25 UT1 and 0°00'00.02" at 21:24:26.
I get an SHA of 0°00'00.00" at 21:24:20 and 359°59'59.97" at 21:24:21.
I get a declination of -0°00'00.02" at 21:24:53 and +0°00'00.00" at 21:24:54.
I think those numbers are reasonable, but I wouldn't completely trust their accuracy. After all, Meeus states that his abbreviated VSOP87 table of coefficients [which I use] should allow "the calculation of the position of the Sun with an error not exceeding 1" between the years -2000 and +6000."1
I remember someone here posting an image which nicely explained why the times are different. But I can't remember who it was. Anyway, I don't think it makes much difference. Saying it happened late on March 20th is close enough, IMHO.
Cheers!
Sean C.
1. Jean Meeus, Astronomical Algorithms, 2nd Ed. (Richmond: Willmann-Bell, 1998), 166.
