An artist's conception of the fast blast wave from Eta Carinae's 1843 eruption, which today has caught up with a slow-moving shell ejected in a previous outburst about 1,000 years ago, producing a bright fireworks display that heats the older shell and makes it emit X-rays (orange). The well-known two-lobed "Homunculus" nebula, a slow-moving shell of gas and dust also produced in the 1843 eruption, is shown closer to the star, which is a hot blue supergiant. (Credit: Gemini Observatory artwork by Lynette Cook)From Science Daily:
ScienceDaily (Sep. 11, 2008) — Eta Carinae, the galaxy's biggest, brightest and perhaps most studied star after the sun, has been keeping a secret: Its giant outbursts appear to be driven by an entirely new type of stellar explosion that is fainter than a typical supernova and does not destroy the star.
Reporting in the Sept. 11 issue of Nature, University of California, Berkeley, astronomer Nathan Smith proposes that Eta Carinae's historic 1843 outburst was, in fact, an explosion that produced a fast blast wave similar to, but less energetic than, a real supernova. This well-documented event in our own Milky Way Galaxy is probably related to a class of faint stellar explosions in other galaxies recognized in recent years by telescopes searching for extragalactic supernovae.
"There is a class of stellar explosions going off in other galaxies for which we still don't know the cause, but Eta Carinae is the prototype," said Smith, a UC Berkeley postdoctoral fellow.
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