Astronomers spot fastest ever nova explosion

Studying the rare event may help scientists to gain insights about the death of stars and the evolution of the universe.

© Mark Garlick

The shortest-ever-lived nova has been spotted by a team of US astronomers. Dubbed V1674 Hercules, the cosmic explosion occurred on 12 June 2021 and was so bright that it could be seen by the naked eye.

Novae are created by the explosion of white dwarf — the very dense leftover core of a star — and a nearby companion star. Over time, the white dwarf sucks matter away from its companion, which then heats up and triggers an uncontrolled explosive burst of energy.

Typically novae fade over several weeks, however V1674 Hercules lasted just over 24 hours – an extremely rare occurrence.

“It was only about one day, and the previous fastest nova was one we studied back in 1991, V838 Hercules, which declined in about two or three days,” said co-researcher Prof Sumner Starrfield, an astrophysicist based at Arizona State University School of Earth and Space Exploration.

The material ejected by novae eventually end up forming new stellar systems, our own Solar System was formed in the same way. This whole process plays an important role in the cycle of matter in space.

Astronomers also hope that by studying novae they can learn more about the lifecycle of binary systems – a process that is not well understood.

“We’re always trying to figure out how the solar system formed, where the chemical elements in the solar system came from,” said Starrfield.

“One of the things that we’re going to learn from this nova is, for example, how much lithium was produced by this explosion. We’re fairly sure now that a significant fraction of the lithium that we have on the Earth was produced by these kinds of explosions.”

The team now plan to further study the cause of the outburst and the processes that led to it, the reason for its record-breaking brevity and its unusual brightness.

Source: BBC