Webb spots two rare lensing patterns in one galaxy cluster [2]

NASA highlighted a Webb image on October 9, 2026, in which a galaxy cluster’s gravity makes distant galaxies appear repeatedly across the frame, including two rare configurations called swallowtails. For astronomers, that distortion is useful: it magnifies objects that would otherwise be too faint to study.

The golden galaxies belong to the foreground cluster MACS J0454.1-0300. The orange shapes crowded around them are galaxies farther behind it, with their light bent and amplified through a process called gravitational lensing. NASA’s post follows the image’s original release on September 29, 2026, rather than announcing a new observation today.

What the repeated images reveal

ESA/Webb says researchers found two examples of a rare arrangement that produces four or more images of parts of the same background galaxy, the first reported occurrence of this configuration twice within one cluster. The researchers’ January 15, 2026, preprint names these swallowtail configurations: the background source crosses a specially shaped boundary of strong magnification, producing several nearby images of its small features, and the authors also describe the pair as a first. One involves a galaxy group seen roughly 2 billion years after the Big Bang; the other shows a galaxy from around 800 million years after it. The paper gives the corresponding cosmic ages as 2.18 billion and 800 million years. These are repeated views of distant objects, so counting every visible shape as a separate galaxy would give the wrong picture.

Hubble had already photographed this cluster in an image released on March 24, 2014. Its accompanying description put the cluster’s mass at roughly 180 trillion Suns, enough to bend passing light into sweeping arcs. The cluster was serving as a natural magnifying glass well before Webb took this view.

The next step is to watch for individual stars. ESA/Webb says Webb observing program 5058, led by Lukas Furtak, plans to monitor a lensed background galaxy for signs of highly magnified stars from the universe’s first billion years. A confirmed detection would establish that an individual star from that early era can be distinguished within its distant host galaxy through gravitational magnification.