Light from farthest quasar makes 12bn year journey

It's not quite on the edge of the universe but it does rank as the most distant object yet discovered by astronomers.

A specialised telescope at Apache Point, New Mexico, recorded the object, a quasar, last month. It is now known to be farther away than any other astral body yet found and is so far away that the pinpoint of light we see today left its distant source perhaps 11 or 12 billion years ago.

Such discoveries excite the world's astronomers because they can provide information about the universe when it was young. The new found quasar was formed a mere one billion years after the Big Bang which marked the birth of the universe.

It is so far away that it has taken all the time since then to reach us. We see it as it was all those aeons ago even though the original object is probably long since dead and gone.

"Because it is so exceptionally luminous, it provides a wonderful opportunity to study the universe when the galaxies that we see today were young, or perhaps before they had even been born," stated Dr Robert Lupton of Princeton University.

Quasars are unusual objects which are star-like but not stars. They are compact, luminous objects thought to be powered by spectacularly powerful black holes as massive as and with the gravitational pull of a billion suns.

The quasar was spotted as part of the Sloan Digital Sky Survey, a joint project operated by astronomers in the US, Japan and Germany and funded by the Alfred P Sloan Foundation. This uses a special-purpose telescope with a 2.5 metre diameter mirror that points towards the stars and records the presence of anything it can find through a single "pinhole" of the sky.

It is so sensitive, however, that this tiny window on the universe might deliver distance information on 20,000 objects per square degree. The plan is to survey 10,000 square degrees or about a quarter of the sky, recording information on 200 million celestial objects. About a million of these will be quasars but very few will be as far away as the newly discovered quasar.

Confirmation that the quasar was a record-breaker came via scientists from the University of California, Berkeley and the Space Telescope Science Institute using the world's largest telescope, the Keck instrument in Hawaii which has a 10 metre diameter mirror.