Academics at Oxford University are working to identify a cosmic mystery which has until now lurked unnoticed in specialist archives.

The phenomenon was first spotted by an armchair astronomer who took part in the Galaxy Zoo project, which enlists the help of amateur star gazers to classify cosmic images that computers cannot identify.

Hanny's Voorwerp - which translates literally as 'Hanny's object' is named after Hanny van Arkel, a Dutch schoolteacher who discovered it. And it is baffling scientists at the university.

They are now hoping that the Hubble Space Telescope will help solve the mystery.

Dr Chris Lintott, of Oxford University, said: "Hanny is one of our 150,000 armchair astronomers, who log on and give detailed classifications of images online. At first we thought what she found was a distant galaxy, but then we realised there were no stars in it, so it must be a cloud of gas.

"What was particularly puzzling was that the gas was so hot - more than 10,000C - when there were no stars around it to heat it up.

"What we think we are looking at now is light from a quasar - the bright stormy centre of a distant galaxy powered by a supermassive black hole."

A black hole is a region of space with a gravitational pull so powerful that nothing, not even light, can avoid it.

Dr Lintott added: "Its rather like examining the scene of a crime where we know the culprit must be lurking in the shadows."

Miss van Arkel, who made the discovery from her home in the Netherlands, said she only learned of the project through her love of rock band Queen - and its guitarist Brian May.

The musician recently completed a PhD in Astronomy and worked with Dr Lintott and Sir Patrick Moore on a book about the history of the universe.

Miss van Arkel added: "He was writing about the project because of his own love of astronomy and through his work with Dr Lintott.

"I decided to see what it was about, and I became really interested.

"It's amazing to think amateurs like myself can spot things like this because of a complete coincidence."

Dr Lintott added: "Brian is involved, and will probably be slightly put out that he didn't make the discovery himself!"