A team of astronomers has identified the closest-ever Einstein ring, a rare phenomenon where light from a distant galaxy is bent by the gravity of an adjacent galaxy. This discovery was previously thought to be impossible to observe and would have required a powerful enough telescope.
The ring, shaped like an oval, surrounds a far-off galaxy called NGC 6505, which is about 600 million light years away. However, the team also discovered that this galaxy is actually bending the light of another, even more distant galaxy behind it, approximately 6 billion light years from Earth.
The discovery was made using data from the Euclid telescope, which scans billions of galaxies across a vast area of the night sky. The team found an abundance of evidence for the Einstein ring, including its exceptionally bright appearance and four distinct images of the faraway galaxy.
This close proximity to Earth allows scientists to test Albert Einstein’s theory of general relativity in ways that are not possible with other, more distant lenses. By measuring the mass of the lensing galaxy and the speed of stars, researchers can verify whether their gravity theories align.
While this discovery is a significant breakthrough, it also raises questions about the nature of dark matter. The team found a slightly higher mass estimate for the galaxy than expected, which could be attributed to dark matter clumping together in the centre. Further research will be needed to confirm this finding.
This remarkable discovery not only sheds light on the universe’s mysterious phenomena but also provides new opportunities for scientists to refine our understanding of gravity and its role in shaping the cosmos.
Source: https://www.newscientist.com/article/2467413-stunning-image-shows-the-closest-ever-einstein-ring