Dying Star Betelgeuse Keeps Its Cool ... and Astronomers Are Puzzled

The bright, red star Betelgeuse, in the constellation Orion, has entered the twilight of its life. Like many stars of a similar size that reach the end of the road, Betelgeuse is slowly shedding its mortal coil — by ejecting much of its mass out into space. This phase of star death is extremely common in the universe — in about 5 billion years, when the sun starts to die, it too will become a "red giant." It will shed much of its mass and  swell to such an enormous size that it