Star system

A gravitationally bound system of one or more stars and the planets, smaller bodies, and other objects that orbit them.

Star: A luminous sphere of plasma held together by gravity and powered by nuclear fusion in its core. A star supplies the central mass and energy around which a star system forms.
Protoplanetary disk: A rotating disk of gas and dust surrounding a young star, from which planets can form. The disk is the material reservoir from which many planetary systems develop.
Solar System: The Sun and the objects gravitationally bound to it, including eight planets, dwarf planets, moons, and small bodies. It is the nearby example whose structure anchors the idea of a star system.
Binary star: A system of two stars that orbit their common center of mass. It is a specific multiple-star arrangement within the broader class of star systems.
Orbit: The path an object follows around another object under the influence of gravity. Orbital motion determines how planets and smaller bodies move within a star system.
Planetary migration: A change in a planet's orbit caused by interactions with a disk, other planets, or small bodies. Migration helps explain why planets may end far from their formation locations.
Alpha Centauri: The nearest stellar system to the Solar System, consisting of the binary stars Alpha Centauri A and B and the red dwarf Proxima Centauri. Its multiple stars show that a system need not have a single central star.
Multiple star system: A gravitationally bound system containing three or more stars. It extends the single- and binary-star cases to more complex stellar groupings.
Gravity: The fundamental interaction by which masses attract one another. Its attraction binds the system and governs the motions of its members.
Orbital resonance: A gravitational relationship in which orbiting bodies have orbital periods in a ratio of small integers. Resonances can organize orbital spacing and transfer energy between system members.

Linked from 53 pages