Astronomers have captured a striking image of 17 concentric dust rings resembling a cosmic fingerprint in the latest observations from the James Webb space telescope.
The formation was created by the interaction of two giant stars, known collectively as the Wolf-Rayet 140 binary, more than 5,000 light years from Earth. The rings are created every eight years when the stars pass close to each other in their elongated orbit. During their close approach, the solar winds from the stars collide, causing the gas streaming from the stars to be compressed into dust.
“Like clockwork, WR140 puffs out a sculpted smoke ring every eight years, which is then inflated in the stellar wind like a balloon,” said Prof Peter Tuthill of the Sydney Institute for Astronomy at the University of Sydney, a study co-author. “Eight years later, as the binary returns in its orbit, another ring appears, the same as the one before, streaming out into space inside the bubble of the previous one, like a set of giant nested Russian dolls.”
The 17-ring structure was produced over about 130 years and spans a region of space larger than our own solar system.
The WR140 binary is comprised of a huge Wolf-Rayet star and an even bigger blue supergiant star. A Wolf-Rayet is born with at least 25 times more mass than our Sun and is a star that is nearing the end of its stellar lifecycle. Burning hotter than in its youth, a Wolf-Rayet star generates powerful winds that push huge amounts of gas into space – the one in this binary is thought to have lost at least half its original mass through this process.
As carbon and heavy elements are blown into space, they are compressed at the boundary where the winds from both stars meet.
“The wind from the other star sweeps the gas into lanes and you have enough of the material close together that it condenses into dust,” said Dr Olivia Jones, Webb fellow at the UK Astronomy Technology Centre and a co-author of the study. “Not only is this a spectacular image but this rare phenomenon reveals new evidence about cosmic dust and how it can survive in the harsh space environments.”
Jones said the latest observations could provide new insights into how the first generation of stars seeded their surroundings with dust and gas that led to subsequent generations of stars in the early universe.
The findings are published in the journal Nature Astronomy.
