Star dies in brightest supernova

[lovuian]

http://news.bbc.co.uk/2/hi/science/nature/6633609.stm


Star dies in brightest supernova
Artist's illustration provided by NASA of SN 2006gy
The supernova was far brighter than any seen before
A massive star around 150 times the size of the Sun has exploded in what is the brightest supernova ever seen, Nasa scientists have said.

Supernovae occur when huge, mature stars effectively run out of fuel and collapse in on themselves.

But scientists believe this one was obliterated in an explosion which blasted all its material into space.

And astronomers say a star in our own Milky Way galaxy could be about to perform the same celestial fireworks.

more...
And the Eta Carina is due to explode anytime in our Milky Way Galaxy what a show that will be
We may get to see it in our lifetimes
made a video on it

http://www.youtube.com/watch?v=3PISARHyfGE

[qdemn7]

1. Supernova affecting Earth

http://en.wikipedia.org/wiki/Supernova

Impact on Earth

A near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth (roughly fewer than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth's case, gamma rays induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. The gamma ray burst from a nearby supernova explosion has been proposed as the cause of the end Ordovician extinction, which resulted in the death of nearly 60% of the oceanic life on Earth.

Speculation as to the effects of a nearby supernova on Earth often focuses on large stars as Type II supernova candidates. Several prominent stars within a few light centuries from the Sun are candidates for becoming supernovae in as little as a millennium, such as Betelgeuse, a red supergiant 427 light-years from Earth. Though spectacular, these "predictable" supernovae are thought to have little potential to affect Earth.

Recent estimates predict that a Type II supernova would have to be closer than eight parsecs (26 light-years) to destroy half of the Earth's ozone layer. Such estimates are mostly concerned with atmospheric modeling and considered only the known radiation flux from SN 1987A, a Type II supernova in the Large Magellanic Cloud. Estimates of the rate of supernova occurrence within 10 parsecs of the Earth vary from once every 100 million years to once every one to ten billion years.

Type Ia supernovae are thought to be potentially the most dangerous if they occur close enough to the Earth. Because Type Ia supernovae arise from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. One theory suggests that a Type Ia supernova would have to be closer than a thousand parsecs (3300 light-years) to affect the Earth. The closest known candidate is IK Pegasi (see below).

In 1996, astronomers at the University of Illinois at Urbana-Champaign theorized that traces of past supernovae might be detectable on Earth in the form of metal isotope signatures in rock strata. Subsequently, iron-60 enrichment has been reported in deep-sea rock of the Pacific Ocean by researchers from the Technical University of Munich.