Tags: Star.
Betelgeuse (/ˈbiːtəldʒuːz/ /ˈbɛtəldʒuːz/ or /ˈbiːtəldʒuːs/) also known by its Bayer designation Alpha Orionis (α Orionis α Ori) is the ninth-brightest star in the night sky and second-brightest in the constellation of Orion. Distinctly reddish it is a semiregular variable star whose apparent magnitude varies between 0.2 and 1.2 the widest range of any first-magnitude star. Betelgeuse is one of three stars that make up the Winter Triangle and it marks the center of the Winter Hexagon.
