Orion was the name of a constellation which was light years from Earth in the Mutter's Spiral galaxy. Though constellations typically contain stars hundreds of light-years apart, Orion was typically used to discuss a specific group of star systems. Once such member was the double star system known as Bellatrix.
The Osirian race placed great importance on the constellation. (MA: Sands of Time)
In the 26th century, Orion was settled by androids fleeing from persecution in the Earth Empire. They set up an independent society that demanded any Humans in their territory must accept android rule or get out. The Earth Empire could not abide the restriction, and waged the Orion War in retaliation. (BFA: Sword of Orion)