Superkilonova: Double Explosion Could Be First Ever Seen
Artist’s concept of a hypothesized superkilonova. First, a massive star explodes in a supernova, which generates elements like carbon and iron (left). In the aftermath, 2 neutron stars are born, at least 1 of which is believed to be less massive than our sun (middle). The neutron stars spiral together, sending gravitational waves rippling through the cosmos, before merging in a dramatic kilonova (right). Kilonovas seed the universe with the heaviest elements, such as gold and platinum, which glow in red light as depicted here. Image via Caltech/ K. Miller and R. Hurt (IPAC)/ Keck Observatory.
A team of astronomers using numerous telescopes, including the W. M. Keck Observatory on Maunakea, Hawaii Island, have discovered a possible superkilonova that exploded not once but twice. The evidence shows this oddball event may be a first-of-a-kind superkilonova, or a kilonova spurred by a supernova. Astronomers have hypothesized such an event, but it’s never been seen before.
Mansi Kasliwal, Caltech professor of astronomy and director of Palomar Observatory, is lead author of a new study describing the findings. The researchers published the peer-reviewed study in The Astrophysical Journal Letters on December 15, 2025.
Supernovas and kilonovas
When the most massive stars reach the ends of their lives, they blow up in spectacular supernova explosions, which seed the universe with heavier elements such as carbon and iron. Another type of explosion – the kilonova – occurs when a pair of dense, dead stars called neutron stars smash together, forging even heavier elements, such as gold and uranium. The heavy elements created by both of these explosions are among the basic building blocks of stars and planets.
So far, only one kilonova has been unambiguously confirmed to date, a historic event known as GW170817, which took place in 2017. In that case, two neutron stars smashed together, sending ripples in space-time known as gravitational waves, as well as light waves, across the cosmos. The National Science Foundation’s Laser Interferometer Gravitational-Wave Observatory (LIGO) and its European partner Virgo detected the gravitational waves from the blast. And dozens of ground-based and space telescopes around the world detected the explosion in light waves.
(Source: earthsky.org)
