As a Star Reaches the End of Its Life, the Countdown to a Supernova Begins - Michael D. Lemonick

http://www.time.com/time/health/article/0,8599,2106904,00.html?xid=gonewsedit&google_editors_picks=true



In 1843, Eta Carinae gave a hint that the end might be very near when the hitherto nondescript body flared up to become the second-brightest star in the sky, after Sirius. It stayed that way for 20 years or so, then faded and left behind a majestic, billowing cloud of gas known as the Homunculus Nebula. Eta Carinae lost some 10% of its substance in this event, which astronomers now call a "supernova impostor," after which it has returned to relative quiet — or what passes for quiet in such an unstable object.