Hubble and Webb telescopes team up to study gigantic galaxy cluster

Two of NASA's premium space observatories, the Hubble Space Telescope and the James Webb Space Telescope, have teamed up to study a pair of colliding galaxy clusters called MACS0416. Located about 4.3 billion light-years from Earth, the galaxy clusters will eventually combine to form an even bigger cluster.

The above picture of galaxy cluster MACS0416 was created by combining infrared observations from Webb with visible-light data from Hubble. The bluest galaxies seen by Hubble are relatively nearby and often show intense star formation while the redder galaxies detected by Webb tend to be more distant, or else contain copious amount of dust.

The image reveals a wealth of details, thanks to the combined power of both telescopes. The Webb observations were aimed at searching for objects varying in observed brightness over time, called transients. The researchers successfully identified 14 such transients across the field of view.

One of those transients stood out in particular. Nicknamed "Mothra" by the researchers, the transient is a star that is magnified by a factor of at least 4,000 times. According to the science team behind this discovery, Mothra is magnified not only by the gravity of MACS0416, but also by an object called "milli-lens" that likely weighs about as much as a globular star cluster.

"We are building on Hubble's legacy by pushing to greater distances and fainter objects," said Rogier Windhorst of Arizona State University, principal investigator of the PEARLS program (Prime Extragalactic Areas for Reionization and Lensing Science), which took the Webb observations.

She comes in colors everywhere 🎵Webb and @NASAHubble have brought you one of the most colorful and comprehensive views of the universe ever taken. This image showcases MACS0416, a gigantic galaxy cluster located about 4.3 billion light-years from Earth: https://t.co/g3IPGg6AdT pic.twitter.com/3JTKaj5EZN

— NASA Webb Telescope (@NASAWebb) November 9, 2023