Binary star system

A binary star system is a group of two stars in very close proximity, usually in orbit around each other.

In Real Life

 * Alpha Centauri - If Proxima orbits the two stars, then it would be a trinary system.

In Fiction

 * Klendathu System - Starship Troopers
 * Risa System - Star Trek
 * Tatooine System - Star Wars
 * In 2010, Jupiter becomes a second star thanks to the Monolith aliens, christened Lucifer.