NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Fall Equinox
From: Bill B
Date: 2008 Sep 21, 01:11 -0400
From: Bill B
Date: 2008 Sep 21, 01:11 -0400
Is it possible to predict, within a second or two, an equinox using the Nautical almanac? Internet sites state 15:44:18 UTC, 22 September, 2008 as the moment of fall equinox. The almanac has a nominal "d" of 1' per hour, but 0'.9 d as the interval bracketing the transition from north to south declination of the sun. Interpolation gets me within a couple of minutes of the published time, but rounding in declination seems to make an exact calculation difficult at best. Further complicating matters, IF memory serves a scholarly review (complete with diagrams) of the the relationship between the First Point of Aries, the celestial equator, and the ecliptic pointed out the relationship is not as simplistic as I might have expected. As usual, when memory fails I blame George Huxtable for the post.If once again I am mistaken about the author, would the above-mentioned list guru please give a reference to the date and subject of the post, or re post? Thanks Bill B. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
