So θ Orionis, or the Trapezium of Orion, is a multiple star, probably lying in the midst of the nebula.
When several stars appear in close proximity to each other, they are spoken of, collectively, as a multiple star.
|multiple star |
A system of three or more stars that are bound together by gravity and orbit a common center of mass. The group generally appears as a single star to the naked eye. Astronomers believe that most stars in the universe are part of multiple or binary systems. Alpha Centauri, the closest star to our Sun, is a multiple star system containing three bodies. See also binary star.