From 26e5d1abc3e9a0a74ed7b569baf0c08b788fc898 Mon Sep 17 00:00:00 2001 From: mathar Date: Tue, 27 Jul 2021 13:35:30 +0200 Subject: [PATCH] Astronomical Almanac 2020 Pluto elements (#2 #22) --- libastro/plans.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/libastro/plans.c b/libastro/plans.c index 51fac93..3ddf451 100644 --- a/libastro/plans.c +++ b/libastro/plans.c @@ -45,17 +45,17 @@ pluto_ell ( double mj, /* epoch */ double *ret) /* ecliptic coordinates {l,b,r} at equinox of date */ { - /* mean orbital elements of Pluto. - * The origin of these is somewhat obscure. + /* Mean orbital elements of Pluto. + * Astronomical Almanac 2020 page G3. */ - double a = 39.543, /* semimajor axis, au */ - e = 0.2490, /* excentricity */ - inc0 = 17.140, /* inclination, deg */ - Om0 = 110.307, /* long asc node, deg */ - omeg0 = 113.768, /* arg of perihel, deg */ - mjp = 2448045.539 - MJD0, /* epoch of perihel */ + double a = 39.789, /* semimajor axis, au */ + e = 0.252, /* excentricity */ + inc0 = 17.097, /* inclination, deg */ + Om0 = 110.297, /* long asc node, deg */ + omeg0 = 115.058, /* arg of perihel, deg */ + mjp = 2459000.5 - MJD0, /* epoch of perihel */ mjeq = J2000, /* equinox of elements */ - n = 144.9600/36525.; /* daily motion, deg */ + n = 0.0039; /* daily motion, deg */ double inc, Om, omeg; /* orbital elements at epoch of date */ double ma, ea, nu; /* mean, excentric and true anomaly */