Astronomers capture stunning Einstein's ring 12 billion light years away

Astronomers recently captured Einstein's ring in stunning image of lensed galaxy 12 billion light years away.

Astronomers have discovered that a distant galaxy seen from Earth with the aid of a gravitational lens, appeared like a cosmic ring, because of the highest resolution images ever taken with the Atacama Large Millimeter/submillimeter Array (ALMA).

Forged by the chance alignment of two distant galaxies, this striking ring-like structure was a rare and peculiar manifestation of gravitational lensing as predicted by Albert Einstein in his theory of general relativity. Gravitational lensing occurs when a massive galaxy or cluster of galaxies bends the light emitted from a more distant galaxy, forming a highly magnified, though much distorted image.

In this particular case, the galaxy known as SDP.81 and an intervening galaxy lined up so perfectly that the light from the more distant one forms a nearly complete circle as seen from Earth.

Discovered by the Herschel Space Observatory, SDP.81 was an active star-forming galaxy nearly 12 billion light-years away, seen at a time when the Universe was only 15 percent of its current age. It was being lensed by a massive foreground galaxy that was a comparatively nearby 4 billion light-years away. The new SDP.81 images were taken in October 2014 as part of ALMA's Long Baseline Campaign, an essential program to test and verify the telescope's highest resolving power, achieved when the antennas are at their greatest separation: up to 15 kilometers apart.

The study is published in the Astrophysical Journal, Letters.