In the images that Euclid sent to Earth back in September 2023, evidence was found of the Einstein ring being located very close to Earth.
In the images that Euclid sent to Earth back in September 2023, evidence was found of the Einstein ring being located very close to Earth.
«Even from the first observation I could see it, but after Euclid made additional observations of this area, we were able to see the perfect Einstein ring. For me, who has been interested in gravitational lenses all my life, it was amazing,» said Bruno Altieri, a scientist at the Euclid archive who reviews data coming from the telescope, writes Science Daily.
An extremely rare phenomenon, the Einstein ring, is also called the Einstein–Khvolson ring or Khvolson ring (named after Orest Khvolson). It is formed when light from a galaxy or star passes by a massive object on its way to Earth. Gravitational lensing bends the light, making it appear to come from different places. If the source, lens, and observer are perfectly aligned (syzygy), the light appears as a ring. This means that we can sometimes see light from distant galaxies that would otherwise be hidden.
The Einstein Ring, first discovered by Euclid, is located in a galaxy called NGC 6505, which is about 590 million light-years from Earth. That’s about two steps in cosmic terms, which means it’s pretty close.
The ring around the foreground galaxy is made up of light from a distant, bright galaxy. This background galaxy is 4.42 billion light-years away, and its light has been distorted by gravity on its way to us. This distant galaxy has never been observed before and does not yet have a name.
«The Einstein Ring is an example of strong gravitational lensing,» explains Conor O’Riordan of the Max Planck Institute for Astrophysics in Germany and lead author of the first scientific paper analyzing the ring. He noted that all strong lenses are special because they are very rare, and they are incredibly useful from a scientific point of view. «This one is especially special because it is located so close to Earth, and the alignment makes it very beautiful,» the scientist added.
Thanks to data from Euclid, scientists have been able to learn more about the expansion of the Universe, detect the influence of invisible dark matter and dark energy, and investigate a background source whose light is distorted by dark matter between us and the source.
«I find it very intriguing that this ring has been observed in a well-known galaxy that was first discovered in 1884,» says Valeria Pettorino, ESA’s Euclid project scientist. She noted that this galaxy has been known to astronomers for a very long time, but this ring has never been observed before. «This shows how powerful Euclid is, finding new things even in places we thought we knew well. This discovery is very encouraging for the future of the Euclid mission and demonstrates its fantastic capabilities,» she added.
The European Space Agency’s Euclid observatory was launched into orbit aboard a SpaceX Falcon 9 rocket on July 1, 2023, at 11:11 a.m. ET. Euclid’s overall mission is to search for the invisible dark matter and dark energy that drive galaxy mergers, the expansion of the universe, and the motion of individual stars. With the data, scientists hope to understand how the dark universe behaves to determine the effects of time on our cosmos. Euclid is traveling to Lagrange Point 2, which is about 1 million miles (1.5 million km) from Earth on the opposite side of the sun. It will collect scientific data over a six-year period.
