Hubble pictures dying star 4,000 light years from earth

1.00pm - By CHARLES ARTHUR

It could be a detail from a Michelangelo painting, showing clouds hiding some godhead.

But in fact the butterfly-like "wings" are clouds of gas extending for millions of miles across space, ejected at up to 400 kilometres per second (900,000mph) by the death throes of a star at their centre.

But despite burning with a temperature of at least 250,000 C, fifty times hotter than our own Sun, the star itself is hidden by the blanket of gas and a black belt of cooler gas. These vast clouds of dust and gas will go on to seed new stars in the future, million of years from now.

The object, which has been pictured by the Hubble Space Telescope, is called the "Bug Nebula" (NGC6302) and is the brightest and, some astronomers say, most spectacular such formation ever found.

It lies in the constellation Scorpius (the Scorpion), about 4,000 light years from Earth, and the gases were probably thrown out about 10,000 years ago.

In about five billion years our own Sun will probably suffer a similar fate, expanding to swallow our planet as it turns into a "red giant" before burning out.

Astronomers are interested by the nebula because analysis of the radiation being emitted by the gases suggests they contain hydrocarbons, carbonates, water ice and iron.

The presence of carbonates - molecules containing carbon and oxygen - has previously been thought to indicate the presence of liquid water. But carbonates in nebulas where no liquid water has existed shows the molecules could form through other processes.

"What caught our interest in NGC 6302 was the mixture of minerals and crystalline ice - hailstones frozen onto small dust grains," said Dr Albert Zijlstra, an astronomer at the University of Manchester Institute of Science and Technology, who analysed the image for the journal Astronomy & Astrophysics.

"Very few objects have such a mixed composition."Scientists are also intrigued by the shape of the nebula, where a black band of dust and gas in the middle encircles the dying star. It is that band which actually contains most of the gases thrown out by the star, which is not visible to the eye because it "shines" with ultraviolet light.

"We really don't know what causes the material to be ejected primarily in one plane," said Dr Zijlstra.

Because the star itself is round, it should have thrown out its gas as a sphere. One possibility is that it was rotating so quickly as it heated up that the gases were thrown out in the plane of rotation.

Another is that it has an unseen companion star or object that has pulled the gas in that direction.

Finally, it may have swallowed a giant planet - like the Sun swallowing Jupiter - during its death.

"If you threw Jupiter into the Sun, the Sun would start to spin like mad," said Dr Zijlstra.

That could have led to the violent ejection of gas from the poles and the equator of the star, and thus to the beautiful sight before us.

- INDEPENDENT