Spiral Galaxy Seen Through a Cosmic Lens (Webb & Hubble composite)

A nearly perfect circle of light surrounds a bright core in this image, forming what astronomers call an Einstein ring. What looks like a single distorted galaxy is in fact two: a massive elliptical galaxy in the foreground and a more distant spiral galaxy behind it. The alignment between them is so precise that the light from the background galaxy is stretched and bent into a glowing ring by the gravity of the one in front.

This cosmic illusion is an example of gravitational lensing, a phenomenon predicted by Albert Einstein’s theory of general relativity. Massive objects, such as galaxies or clusters of galaxies, bend the very fabric of spacetime, causing light to curve as it travels past. When the lensing and background galaxies align just right, the result is a complete or partial ring of light.

Such systems offer astronomers a rare opportunity to study galaxies that would otherwise be too faint or distant to observe. In this case, the lensing elliptical galaxy sits within the cluster SMACSJ0028.2-7537, while the lensed spiral galaxy reveals detailed structures of stars and gas that have been magnified by this natural cosmic lens.

This image combines data from Webb’s Near-Infrared Camera (NIRCam) collected during the Strong Lensing and Cluster Evolution (SLICE) survey with additional observations from the Hubble Space Telescope’s Wide Field Camera 3 and Advanced Camera for Surveys.