Betelgeuse

views updated May 21 2018

Betelgeuse (Alpha Orionis) Red supergiant star, the second-brightest in the constellation of Orion. It is a pulsating variable whose diameter fluctuates between 300 to 400 times that of the Sun. Characteristics: apparent mag. 0.85 (mean); absolute mag. 25.5 (mean); spectral type M2; distance 500 light years.