apsis
Either of the points in the orbit of a celestial object that is farthest
from or closest to the body being orbited. The closest point is the periapsis,
the further point the apoapsis. The line joining
these points is called the line of apsides, and is another
name for the major axis of the orbit.
Rotation of the line of apsides in the plane of the orbit is known as apsidal
motion or advance of perihelion
(in the case of a planet orbiting the Sun) or advance of pericenter
(in the case of a binary star). Plural is "apsides." Related
category
• CELESTIAL
MECHANICS
Also on this site: Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|