By SHAWN LOGAN, SUN MEDIA
The Edmonton Sun

EDMONTON -- Call it CSI: Outer Space.

A team at the University of Alberta has cracked the mystery of a massive star that died 11,000 light years from Earth, the light from its explosion only being seen by skywatchers here 330 years ago.



An image provided by NASA is a false-color picture showing the many sides of the supernova remnant Cassiopeia A. (AP/HO/NASA)

The findings, which will appear in the latest edition of the journal Nature, available today, show that the fledgling neutron star, the corpse of its exploded ancestor, has an atmosphere comprised of superheated carbon, far different from the hydrogen atmospheres believed to encircle the remnants of other dead stars.

U of A physics professor Craig Heinke said after months of analyzing inconsistencies in the composition of the neutron star in the Cassiopeia system, the team finally had its eureka moment after testing to see if the unusual nature was something completely different.

"Boom! There it was," he said of the discovery of a 10 cm deep layer of gaseous carbon atmosphere.

"It fit and put the size in the right ballpark -- I was pumped."


The riddle of the supernova, dubbed Cassiopeia A (Cas A) and the youngest neutron star yet discovered, came from unusual heat emanations uncommon in the remnants of other discovered supernovae.

Heinke said the heat was inconsistent with the hydrogen atmospheres discovered around the extraordinarily dense cores of other neutron stars and suggested a different element may have been at play in the 20-km wide remnant.

MAP OUT

And with the apparent shift in elemental composition from a younger neutron star to ones that have aged somewhat (over the course of millenia), researchers will be able to map out the afterlife of exploded stars.

"This discovery helps us understand how neutron stars are born in violent supernova explosions," Heinke said.

"This neutron star has a story to tell -- you have your supernova explosion and inside a bunch of elements are floating around and they start raining down on the neutron star due to its intense gravity."

Supernovae produce most of the minerals that make up the universe including many found on Earth such as gold and silver.

Heinke said the local team will continue to study the neutron star.

http://cnews.canoe.ca/CNEWS/Science/2009/11/05/11642251-sun.html