Central body
Encyclopedia
In astrodynamics
Astrodynamics
Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. The motion of these objects is usually calculated from Newton's laws of motion and Newton's law of universal gravitation. It...

 a central body () is a body that is being orbited by an secondary body
Orbiting body
In astrodynamics, an orbiting body is a body that orbits a primary body .The orbiting body is properly referred to as the secondary body.It is less massive than the primary body ....

, or satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 ().

The central body is properly referred to as the primary body.

Under standard assumptions in astrodynamics:
  • it is more massive than the secondary body (i.e. ),
  • The focus
    Focus
    Focus, FOCUS, or foci may refer to:In science, mathematics or computing:*Focus , selectively concentrating on one aspect of the environment while ignoring other things...

     of its orbit
    Orbit
    In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

    is located at the barycenter of the two bodies.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK