Scientists spot giant ‘Einstein ring’ nearby in space – by accident

Scientists have found a rare “Einstein ring” near Earth –?stumbling on it almost by accident.

The rare phenomenon was spotted in test images from Euclid, a powerful space telescope.

Astronomers took the images to ensure that everything on Euclid was working as it should be. But in those blurry test images, scientists spotted something deserving of more research –?and after a better look it turned out they had seen the rare ring in a relatively nearby galaxy.

The discovery, published in the journal Astronomy And Astrophysics, is of a circle of light created by gravitational lensing around a galaxy 500 million light years away called NGC 6505.

This ring is made up of light from a galaxy 4.42 billion light years away and what can be seen from Earth is distorted by gravity.

The distant galaxy has not been observed before and has not yet been named.

Professor Thomas Collett, from the University of Portsmouth’s Institute of Cosmology and Gravitation, said such rings can help scientists test Albert Einstein’s general theory of relativity.

He said: “This lens is particularly special because it’s in our cosmic backyard: a ‘mere’ 500 million light years away.

“In fact, it’s so close that astronomers first observed the galaxy in the 1880s, but only with the resolving power of Euclid can we now reveal that it’s a gravitational lens.

“Nearby lenses are exciting because they allow us to test the validity of general relativity on astronomical scales.”

Einstein’s general theory of relativity predicts that light will bend around objects in space, so that they focus the light like a giant lens, with this effect being bigger for massive galaxies.

It allows astronomers to see the light from distant galaxies that would otherwise be hidden.

Conor O’Riordan, of the Max Planck Institute for Astrophysics in Germany and lead author of the first scientific paper analysing the ring, said: “An Einstein ring is an example of strong gravitational lensing.

“All strong lenses are special, because they’re so rare, and they’re incredibly useful scientifically.

“This one is particularly special, because it’s so close to Earth and the alignment makes it very beautiful.”

Launched in July 2023, the Euclid mission aims to create a 3D map of the universe by observing two billion galaxies, which will help scientists understand its cosmic history.

Additional reporting by agencies