NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Beginner Meridian Passage Question
From: Andr?s Ruiz
Date: 2004 Sep 9, 12:09 +0200
From: Andr?s Ruiz
Date: 2004 Sep 9, 12:09 +0200
You can see at http://www.geocities.com/andresruizgonzalez/celestial/polaris_eng.html A graphic of Polaris SHA and Declination during this year and 2005 -----Mensaje original----- De: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] En nombre de Noyce, Bill Enviado el: viernes, 03 de septiembre de 2004 15:13 Para: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Asunto: Re: [NAV-L] Beginner Meridian Passage Question > > b) when you think Polaris is directly below or above the pole, add or > > subtract its difference (which you have memorized as about 45'); > > It looks to me that the average declination for Polaris in 2004 was close to 89 d 17'. 90 - > 89 d 17' = 43'. Am I missing some 2nd and 3rd order variables when calculating the distance > of Polaris from PN? Id so, what? For lifeboat navigation, I was assuming (1) a couple of minutes / miles doesn't matter; (2) a round number was easier to remember; and (3) I had the impression Polaris had already passed as close to the pole as it was going to, and was now slowly moving away. I now believe #3 is wrong -- it looks to me as if that happens around 2008, though the motion is less than 0.1' every few years. So if you can remember 44' or 43', use that. -- Bill