hypernovae

What's going to happen to all the stars in the Universe as they get older? Well, just as nothing can live forever, stars can't live forever also. Why? Because they run on fuel: burning hydrogen into helium, for example. When they run out of fuel, something's gotta give. Barbara Ryden reminds us of an excellent and appropriate quote by Dylan Thomas: Do not go gentle into that good night. Rage, rage against the dying of the light. But what exactly happens to the star depends very sensitively on what the mass of the star is. If you've got a tiny little star, less than about 40% of the mass of…
Those of you who keep up with your news may have seen this headline on CNN last week: Star Explodes Halfway Across Universe. What they're talking about is a Gamma-Ray Burst, which was so bright that, despite being 7.5 billion light years (that's 2.3 Gpc) away, it was still visible on Earth with the naked eye. From the article: The aging star, in a previously unknown galaxy, exploded in a gamma ray burst 7.5 billion light years away, its light finally reaching Earth early Wednesday. This is the sort of thing that the SWIFT satellite was designed to detect, pinpoint, and then tell Earth-based…