Why in news?

The European Space Agency’s (ESA) Euclid space telescope has discovered a rare Einstein ring around the galaxy NGC 6505, located 590 million light-years from Earth.

Captured in September 2023 and released recently, the images show a bright central galaxy encircled by a luminous ring.

Astronomers have described the find as extraordinary and lucky, highlighting its significance in Euclid’s early data.

What’s in today’s article?

• NGC 6505
• Einstein Ring
• Need to Study Einstein Rings

NGC 6505

• NGC 6505 is an elliptical galaxy classified as E/S0, located in the Draco constellation in the northern celestial hemisphere.
  • Draco is a constellation in the northern sky that looks like a dragon. 
  • It's the ninth largest constellation and is visible for most of the year from the Northern Hemisphere. 
• It lies about 608 million light-years from the Milky Way and has a diameter of 190,000 light-years.
• Discovered by Lewis A. Swift in 1884, it gained significance in 2025 when the Euclid Space Telescope detected a complete Einstein ring surrounding it.

Einstein Ring

• An Einstein ring is a circular ring of light formed around a galaxy, dark matter, or a cluster of galaxies due to gravitational lensing.
  • Gravitational lensing occurs when a massive celestial object, like a galaxy or galaxy cluster, bends and amplifies the light from a more distant object behind it but along the same line of sight.
  • The object causing the light to bend is called a gravitational lens.
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• The Recently Discovered Einstein Ring
  • In the case of the Einstein ring found by ESA’s Euclid telescope, the galaxy NGC 6505 acted as the gravitational lens, distorting and magnifying the light from a distant unnamed galaxy located 4.42 billion light-years away.
• Rarity and Discovery of Einstein Rings
  • Einstein rings were predicted by Albert Einstein’s general theory of relativity.
  • The first one was discovered in 1987, and while several more have been found, their total number remains unknown.
  • They are extremely rare, with less than 1% of galaxies having an Einstein ring.
  • These rings are not visible to the naked eye and can only be observed through space telescopes like Euclid.

Need to Study Einstein Rings

• Understanding Dark Matter – Einstein rings help study dark matter, which makes up 85% of the universe but cannot be directly detected. Gravitational lensing allows scientists to observe its effects.
• Studying Distant Galaxies – These rings magnify galaxies that would otherwise be invisible, providing insights into their structure and composition.
• Exploring Universe Expansion – By analyzing light from both foreground and background galaxies, Einstein rings help scientists understand how the universe is expanding over time.
• Bridging Science with Everyday Life - The principles of gravitational lensing have applications in medical imaging, optical lens design, and telecommunications.
  • Computational models used in analyzing cosmic distortions also contribute to AI, machine learning, and big data analytics, influencing diverse fields like finance, climate science, and urban planning.