Astronomers have made a groundbreaking discovery, capturing the first visual evidence of a star that exploded twice. This phenomenon, known as a double detonation, challenges our current understanding of how stars explode and could reveal new insights into the evolution of white dwarfs.
The team used the Very Large Telescope (VLT) and its Multi Unit Spectroscopic Explorer (MUSE) instrument to study the remains of supernova SNR 0509-67.5, located 60,000 light-years away in the constellation Dorado. The investigation revealed structures within this explosive wreckage that indicate the progenitor star exploded not once but twice.
The star in question was a white dwarf, a type of stellar remnant formed when a star with a mass similar to the sun runs out of fuel for nuclear fusion. White dwarfs undergo Type Ia supernovas, which are important to astronomers because their light output is uniform, making them “standard candles” for measuring cosmic distances.
The team’s research suggests that double detonations occur when white dwarfs strip material from a donor star, wrapping themselves in a blanket of stolen helium. This envelope becomes unstable and eventually ignites, triggering the first detonation. The initial explosion generates a shockwave that ripples inwards, striking the core of the white dwarf and triggering a second detonation, the actual supernova.
The observation of SNR 0509-67.5 has provided tangible evidence of a double detonation, solving a long-standing mystery about the evolution of white dwarfs. The team’s discovery also offers a visual spectacle, providing astronomers with a unique opportunity to study this rare phenomenon.
“This discovery not only contributes to our understanding of Type Ia supernovas but also provides a visual spectacle,” said Priyam Das, team leader and University of New South Wales researcher. “The evidence we’ve found will help us better understand the evolution of white dwarfs and their role in astronomy.”
Source: https://www.space.com/astronomy/stars/astronomers-capture-incredible-1st-image-of-a-dead-star-that-exploded-twice-how-did-it-happen