Brightest early galaxy nicknamed after Ronaldo

 


Scientists have discovered the brightest galaxy yet found in the early universe that contains the first generation of stars, and have nicknamed it after popular Portuguese football player Cristiano Ronaldo.

These massive, brilliant, and previously purely theoretical objects were the creators of the first heavy elements in history - the elements necessary to forge the stars around us today, the planets that orbit them, and life as we know it, researchers said.


The newly found galaxy, labelled CR7, is three times brighter than the brightest distant galaxy known up to now.

The nickname was inspired by 30-year-old Ronaldo, who is known as CR7.

Astronomers have long theorised the existence of a first generation of stars - known as Population III stars - that were born out of the primordial material from the Big Bang.

These Population III stars would have been enormous - several hundred or even a thousand times more massive than the Sun - blazing hot, and transient - exploding as supernovae after only about two million years.

But until now the search for physical proof of their existence had been inconclusive, researchers said.

A team led by David Sobral, from the University of Lisbon in Portugal, and Leiden Observatory in the Netherlands, has now used ESO's Very Large Telescope (VLT) to peer back into the ancient Universe, to a period known as reionisation, approximately 800 million years after the Big Bang.

Instead of conducting a narrow and deep study of a small area of the sky, they broadened their scope to produce the widest survey of very distant galaxies ever attempted.

The team discovered - and confirmed - a number of surprisingly bright very young galaxies.

One of these, labelled CR7, was an exceptionally rare object, by far the brightest galaxy ever observed at this stage in the universe.

"The discovery challenged our expectations from the start, as we didn't expect to find such a bright galaxy," said Sobral.

"Then, by unveiling the nature of CR7 piece by piece, we understood that not only had we found by far the most luminous distant galaxy, but also started to realise that it had every single characteristic expected of Population III stars.

"Those stars were the ones that formed the first heavy atoms that ultimately allowed us to be here. It does not really get any more exciting than this," Sobral said.

Within CR7, bluer and somewhat redder clusters of stars were found, indicating that the formation of Population III stars had occurred in waves - as had been predicted.

What the team directly observed was the last wave of Population III stars, suggesting that such stars should be easier to find than previously thought.

They reside amongst regular stars, in brighter galaxies, not just in the earliest, smallest, and dimmest galaxies, which are so faint as to be extremely difficult to study, researchers said.