Unveiling one of astronomy's most intricate puzzles, researchers have achieved the rare feat of detecting a gravitationally lensed supernova. The discovery, published in Nature Astronomy, combines the elusive occurrence of a distant star explosion with the phenomenon of gravitational lensing—a foreground galaxy bending light from the explosion towards the observer.
The breakthrough, achieved through rapid optical observations by the Zwicky Transient Facility, brought to light the multiply imaged type Ia supernova, christened SN Zwicky or SN 2022qmx. This unique system was detected due to the predictable brightness of type Ia supernovae, acting as a cosmic yardstick.
With advanced imaging from the Keck telescope, scientists discerned four closely spaced images of the supernova—a striking effect caused by the gravitational lens. The incredibly slight angular separation between these images, corresponding to an Einstein radius of just θE = 0.167″, adds to the phenomenon's rarity.
This extraordinary discovery underscores the crucial role of supernovae in deciphering the intricate properties of galaxy-scale gravitational lenses, which provide insight into the cosmos' deeper complexities, including the impact of galaxy substructures.
