Theta<sup>1</sup> Orionis D (ø<sup>1</sup> Orionis D) is a member of the Trapezium open cluster that lies within the Orion Nebula. It is a B class blue main sequence star with several faint companions.
ø<sup>1</sup> Orionis consists of multiple components, primarily the four stars of the Trapezium cluster (A, B, C, and D) all within one arc-minute of each other. ø<sup>2</sup> Orionis is a more distant grouping of three main stars plus several fainter companions, 1-2 arc-minutes from ø<sup>1</sup>.
ø<sup>1</sup> D itself has a faint optical companion 1.4" away and a spectroscopic companion in a 40-day orbit. Infrared Optical Telescope Array observations suggest another companion at 18.6 mas.