In Einstein’s general relativity, matter and energy bend spacetime.
Gather sufficient mass in one location, and space will severely distort.
When light passes through that distorted region, bending and magnification ensue.
It behaves similarly to an optical lens, but powered by gravity: a gravitational lens.
When the observer, lens, and background objects all align, spectacular features emerge.
Arcs, multiple images, and even complete rings all become possible.
Most often, galaxy clusters make the best gravitational lenses, containing overwhelmingly large masses.
But individually massive, compact galaxies can theoretically serve as gravitational lenses, too.
Such galaxies are rare today, but massive, compact galaxies were common 10-12 billion years ago.
Caught by JWST’s eyes, a distant massive, compact galaxy was found behaving as a gravitational lens.
The lens itself is 17 billion light-years away: 2.3 billion more distant than the prior record-holder.
Another 4 billion light-years behind the lens is a background galaxy, lensed perfectly into an Einstein ring.
The ring-shaped light reveals the lens’s mass: 650 billion Suns, concentrated within only a few thousand light-years.
Multiply imaged features within the ring may yet be resolved within the background galaxy.
With lensing magnification and JWST’s capabilities combined, the Universe comes evermore into focus.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words.