THE MYSTERY of how young stars can form within the deep gravity of black holes has been solved by astrophysicists from the universities of St Andrews and Edinburgh who used a whole year of computer time in their work.

The team made the discovery after developing computer simulations of giant clouds of gas being sucked into black holes, and the new research—published in the latest edition of Science—may help scientists gain better understanding of the origin of stars and supermassive black holes in our galaxy and the universe.

Until now, scientists have puzzled over how stars could form around a black hole, since molecular clouds —the normal birthplaces of stars—would be ripped apart by the black hole’s immense gravitational pull.

However, the new study by Professor Ian Bonnell of St Andrews and Dr Ken Rice from Edinburgh found stars appear to form from an elliptical-shaped disc, the remnant of a giant gas cloud torn apart as it encounters a black hole.

The discovery of hundreds of young stars, of high masses and making oval-shaped orbits around a black hole three million times more massive than the sun, and at the centre of our galaxy, is described as one of the most exciting recent discoveries in astrophysics.

Professor Bonnell said the simulations show young stars can form in the neighbourhood of supermassive black holes as long as there is a reasonable supply of massive clouds of gas from further out in the galaxy.

The simulations, performed on the Scottish Universities Physics Alliance (SUPA) SGI Altix supercomputer, followed the evolution of two separate giant gas clouds up to 100,000 times the mass of the sun, as they fell towards the supermassive black hole.

They show how the clouds are pulled apart by the immense gravitational pull of the black hole and form into spiral patterns.

Part of the cloud is captured by the black hole while the rest escapes.

Professor Bonnell said the fact that stars present around the galaxy’s supermassive black hole have relatively short lifetimes of around 10 million years suggests this process is likely to be repetitive.