 The Orion Nebula contains a very young open cluster , known as the Trapezium due to the asterism of its primary four stars . Two of these can be resolved into their component binary systems on nights with good seeing , giving a total of six stars . The stars of the Trapezium , along with many other stars , are still in their early years . The Trapezium is a component of the much larger Orion Nebula Cluster , an association of about 2 @,@ 800 stars within a diameter of 20 light years . Two million years ago this cluster may have been the home of the runaway stars AE Aurigae , 53 Arietis , and Mu Columbae , which are currently moving away from the nebula at velocities greater than 100 km / s . 
