Chandra maps exploded star

X-rays from iron are scattered into space

By BBC News Online science editor Dr David Whitehouse

Observations of the wreckage of an exploded star have provided the best ever map of the "heavy" elements scattered into space by a stellar explosion.

The Chandra X-ray Observatory, in orbit around the Earth, was able to isolate X-rays coming from atoms of elements including iron, calcium and silicon.

X-rays from Silicon - it may eventually find its way into new planets

Because these elements were made inside the star, the images provide an insight into how such elements are manufactured and thrown into space.

All such "heavy" elements on Earth were made inside giant stars that have long since died and exploded. Our Sun and its planets were formed out of their debris.

Cosmic puzzle

The Cassiopeia A supernova remnant is situated at a distance of 11,000 light-years and is the expanding wreckage of a star that would have been seen to explode about 300 years ago.

Chandra cost $2.8bn

It is a puzzle why astronomers did not detect the explosion at the time.

The stellar remnant is composed mostly of glowing gas heated to a temperature of 50 million degrees Celsius. The gas ploughs through interstellar space sweeping up material as it expands.

Astronomers say that structure seen in the remnant may be due to the explosion being non-symmetrical.

The image highlights the distribution of iron and suggests to scientists that it may have come from specific layers within the original star.

Seeing details of the distribution of the elements will help astronomers understand how space becomes enriched with heavy elements that have been made inside stars.