Files Description

Each VSOP2013 file corresponds to a planet and contains trigonometric series, functions of time (Periodic series and Poisson series), that represent the 6 elliptic elements of the planet:

Variable 1	a = semi-major axis (ua)
Variable 2	λ = mean longitude (radian)
Variable 3	k = e cos ω
Variable 4	h = e sin ω
Variable 5	q = sin(i/2) cos Ω
Variable 6	p = sin(i/2) sin Ω

with:

• e : eccentricity

• ω : perihelion longitude

• i : inclination

• Ω : ascending node longitude

VSOP2013 series are characterized by 3 parameters:

• the planet index 1-9 from Mercury to Pluto,

• the variable index 1-6 for a, λ, k, h, q, p,

• the time power α.