People don’t always shine at their brightest as they near the ends of their lives. But stars do. They can shine hundreds of times brighter than when they were in the prime of life — but only for a little while. After that, they quickly fade away.
An example is Tarazed, in Aquila, the eagle. The constellation’s brightest star, Altair, is in the east at nightfall, at the lower right corner of the bright Summer Triangle. Tarazed is just a couple of degrees above Altair.
The star is only about a hundred million years old, compared to four and a half billion years for the Sun. But it’s passed the end of its “normal” lifetime because it’s almost six times as massive as the Sun.
Heavier stars “burn” the hydrogen in their cores at a furious rate, quickly converting it to helium. When that happens, the core gets smaller and hotter, allowing it to burn the helium to make carbon. That causes the star’s outer layers to puff up to gigantic proportions.
And that’s what’s happened to Tarazed. It’s about a hundred times the diameter of the Sun. That makes it shine about 2500 times brighter than the Sun. And that makes it easy to see even though it’s almost 400 light-years away.
Before long, though, Tarazed will cast its outer layers into space. That will leave only its dead core — a ball of carbon and oxygen that’s as massive as the Sun but only about as big as Earth: a white dwarf — a hot but small ember slowly cooling through the long cosmic night.