The European Space Agency’s Euclid space telescope has captured an extraordinary image of an Einstein ring, a rare cosmic phenomenon where light from a distant galaxy bends around another due to gravitational lensing. The striking ring of light encircles the center of the galaxy NGC 6505, located about 590 million light-years away in the constellation Draco—considered relatively close in astronomical terms.
This stunning visual is created by light from another galaxy positioned 4.42 billion light-years away, which remains unobserved and unnamed. The intense gravitational pull of NGC 6505 bends and magnifies the distant galaxy’s light, forming a nearly perfect ring around it. The discovery, published in Astronomy and Astrophysics on February 10, 2025, highlights the immense power of gravitational lensing predicted by Albert Einstein’s theory of relativity.
Bruno Altieri, a Euclid archive scientist, first noticed signs of the Einstein ring in 2023 during the spacecraft’s early testing phase. “Even from that first observation, I could see it, but after Euclid made more observations, we could see a perfect Einstein ring,” Altieri said. He described the discovery as “amazing,” especially given his lifelong interest in gravitational lensing.
Einstein rings occur when the light from a distant galaxy bends around a foreground galaxy due to its gravitational field. This effect, predicted by Einstein’s general theory of relativity, not only distorts space-time but also bends light paths, creating these mesmerizing structures. When the alignment is perfect, the light forms an almost complete circle around the lensing galaxy.
These rare events are scientifically valuable, providing crucial insights into cosmic expansion, the nature of dark matter, and the effects of dark energy. The newly captured Einstein ring, due to its proximity to Earth, could become a key subject for future astrophysical studies.
