Definitions

# Central body

In astrodynamics a central body ($m_1,$) is a body that is being orbited by an orbiting body ($m_2,$). Under standard assumptions in astrodynamics:

• it is more massive than the orbiting body by several orders of magnitude (i.e.
• it is a center of an inertial frame of reference for the orbiting body,
• it is in the focus (or one of the two) of the orbiting bodies' orbit.