BBC Science. Jonathan Amos. 15 Feb 2004

The farthest object in the Universe yet detected has been seen by scientists using the Hubble and Keck telescopes.

It is so distant its light must have set out [13 Billion years ago] when the Universe was just 750m years old […].

The new object was first seen in a series of observations of a cluster of galaxies known as Abell 2218. The object is not in the cluster but situated a long way behind it. Abell 2218 was simply used as a “gravitational lens” – a massive foreground object that can bend and magnify the light of objects much further away.

Gravitational lensing is a remarkable astronomical trick, first predicted by Einstein, that allows scientists to probe regions of the Universe that are estimated to be 13bn light-years away – to look back in time to when some of the very first stars were shining.

The Hubble images were analysed to work out the new object’s red-shift, which measures the degree to which its light is being stretched by the expansion of the Universe. The greater the red-shift, the more distant the object and the earlier it is being seen in cosmic history. The Hubble data suggested a redshift of 6.6, but follow-up observations with the 10-metre Keck telescopes on Hawaii indicated the new object probably has a redshift closer to 7.0 – a record.

“The new object is a small and compact system of stars,” said Professor Ellis. “It’s about 2,000 light-years across; our own galaxy by comparison is about 60,000 light-years across. It is forming stars prodigiously and is a very energetic source, so it may be an example of an object from that early time [just after the “Dark Ages”] that is the first of its kind to form in the Universe.”

The term “Dark Ages” was coined by the English Astronomer Royal, Sir Martin Rees, to signify the period in cosmic history when hydrogen atoms first formed but stars had not yet had the opportunity to condense and ignite.