Orion's Belt. Optical image of the group of stars known as Orion's Belt, in the constellation Orion. North is at top. The belt comprises the three bright stars (from left to right) Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis) and Mintaka (Delta Orionis). Orion is a large and prominent constellation that straddles the celestial equator, making it equally visible from the northern and southern hemispheres.