Definition: Betelgeuse is the brightest star in the constellation of Orion. It can be found in the night sky by locating the three bright stars, which make up Orion's belt. Directly above these three stars, lie two more bright stars, which represent Orion's shoulders. The brightest and uppermost of these two stars is Betelgeuse and it has a reddish colour. The illustration depicts Betelgeuse lying in the armpit of Orion's upraised right arm.