Trapezium

…type of multiple star, the Trapezium (named for its prototype in Orion), as well as supergiants, binaries, gaseous nebulas, and globules. Associations are relatively homogeneous in age. The best distance determinations are from spectroscopic parallaxes of individual stars—i.e., estimates of their absolute magnitudes made from studies of their spectra. Most…

…is not single but a compact quadruple system.