Super-distant Dragon Arc galaxy pictured in extraordinary detail

The Dragon Arc galaxy appears twice in this Hubble image: once on the left, in a normal image, and once as the drawn-out smear of light next to it. Credit: NASA

January 8, 2025

Ellen Phiddian

Astronomers have used a trick of gravity and the James Webb Space Telescope (JWST) to picture 44 individual stars in a galaxy 6.5 billion light-years away.

The galaxy, dubbed the Dragon Arc, hails from a time when the Universe was half its current age.

The observation, which uses a technique called gravitational lensing, marks the largest number of individual stars seen in the distant Universe.

“To us, galaxies that are very far away usually look like a diffuse, fuzzy blob,” says Yoshinobu Fudamoto, an assistant professor at Chiba University in Japan, and lead author on a paper describing the research, published in Nature Astronomy.

“But actually, those blobs consist of many, many individual stars. We just can’t resolve them with our telescopes.”

Instead, the team used the laws of physics. Very massive objects, like galactic clusters, cause a natural magnification with their strong gravitational fields. This is gravitational lensing.

More:
https://cosmosmagazine.com/space/astronomy/dragon-arc-galaxy-pictured/