Eta Carinae, one of the most massive and luminous stars known, is tearing itself apart. A century ago it puffed out a giant cloud of gas. Recently it started acting up again and abruptly doubled in brightness. Despite its great distance, about 7,500 light-years, Eta Carinae is now visible to the naked eye in the Southern Hemisphere. It will likely explode as a supernova within 10,000 years, or maybe sooner.
When it does, it will briefly outshine every other star in the sky. Astronomers are watching the changes with excitement. "This may be a unique situation, seeing a star in detail just before it becomes a supernova," says Ted Gull of NASA's Goddard Space Flight Center.