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Re: When is the Autumnal Equinox?
From: Paul Hirose
Date: 2011 Sep 11, 15:32 -0700
From: Paul Hirose
Date: 2011 Sep 11, 15:32 -0700
I wrote: > The notion of the ecliptic as the apparent path of > the Sun must be abandoned in faver of the mean plane of the orbit of the > Earth - Moon barycenter (center of gravity) about the solar system > barycenter. More precisely, a committee of the International Astronomical Union recommended this definition for the pole of the ecliptic: "the mean orbital angular momentum vector of the Earth-Moon barycenter in an inertial reference frame." That was adopted in 2006. Their paper discusses some of the issues with defining an ecliptic and equinox. http://syrte.obspm.fr/journees2005/s2_02_Hilton.pdf --
