How our bones are linked to calcium from exploding star

A new type of exploding star that gives rise to vast amounts of calcium – which could end up being incorporated into our bones – has been discovered in a nearby galaxy by astronomers.

The exploding star or supernova – one of the biggest explosions in space – was first detected in 2005 in the nearby spiral galaxy of NGC1032, but more recent studies have revealed that it is different to any other known supernovae. Supernova SN 2005E, as it is called, is rich in calcium, said Professor Alex Filippenko, an astronomer that the University of California, Berkeley.

"With the sheer numbers of supernovae we're detecting, we're discovering weird ones that may represent different physical mechanisms compared with the two well-known types, or may just be variations of the standard themes," Professor Filippenko said.

"But SN 2005E was a different kind of 'bang'. It and the other calcium-rich supernovae may be a true suborder of supernovae, not just one of a kind," he said. "We know that SN 2005E came from the explosion of an old, low-mass star because of its specific location in the outskirts of a galaxy devoid of recent star formation. And the presence of so much calcium in the ejected gases tells us that helium must have exploded in a nuclear runaway."

Supernovae result from the collapse of a very massive star or by thermonuclear explosions on the surface of white dwarf stars composed mainly of carbon and oxygen, said Dae-Sik Moon of the University of Toronto, a co-author of one of the studies into the supernova published in the journal Nature.

"But this one, although it appears to be from a white dwarf system, is devoid of carbon and oxygen. Instead it's rich in helium. It's surprisingly different," Dr Moon said. "The supernova explosion is the most energetic and brilliant event that happens in the universe."