Longitude of perihelion

Longitude of Perihelion
The sum of the longitude of the ascending node and the argument of perihelion.

The Longitude of Perihelion
The perihelion and aphelion are precessing, advancing eastward along the ecliptic about 11 arcseconds per year in relation to the fixed stars.

Mean Orbital Velocity in kilometers per second Axial incl Inclination of the rotation axis in degrees (obliquity) Oblate Oblateness Ascend Longitude of the ascending node Perihelion Longitude of perihelion Equilib Equilibrium temperature in Kelvins ...

The argument of perihelion is also defined as the angle between the ascending node (Ω) and the perihelion of the orbit. A related quantity is the longitude of perihelion, Ï-, although the distinction between these two quantities is often blurred.

Terms of annual aberration depending on the eccentricity and longitude of perihelion of the Earth (abbreviation for Ecliptic Aberration). [S92]
Aberration, Planetary ...

Note that in systems (like the Solar System) in which the inclinations of the orbits are small, it is hard to separate from , so another angle, the longitude of perihelion (this is an alternative form of the greek letter and so is pronounced "pi").

It is the angle between the ascending node and the perihelion, measured in the orbital plane. Adding it to the longitude of the ascending node approximately (when the orbital inclination is small) gives the longitude of perihelion of the body in its ...

See also: Planet, Longitude, Perihelion, Orbit, Elements