Artwork created by the strong stellar wind of the Wolf-Rayet star that will become a black hole
The ‘James Webb Space Telescope’ (JWST) captured a scene where the powerful stellar wind wolf-Rayet star formed concentric rings of dust like tree rings.
According to the National Aeronautics and Space Administration (NASA), astronomer Ryan Lau of the National Laboratory of Optical and Infrared Astronomy (NOIRLab) observed the binary system ‘Wolf-Rayer (WR) 140’ in the constellation Cygnus, about 5,000 light-years from Earth, with the Webb telescope. The results of the analysis of 17 dust rings were published in the scientific journal Nature Astronomy.
The research team suggested that these dust rings form when the two stars that make up WR-140 come close to the Sun-Earth distance about every eight years, and the stellar winds collide and compress the gas.
The Webb telescope showed off its state-of-the-art performance by observing 17 dust rings, which were previously only visible through terrestrial telescopes.
Webb’s ‘Mid-Infrared Instruments’ (MIRI) scoured the coolest dust rings with the longest wavelengths, and MIRI spectroscopy revealed that the dust was mostly composed of material ejected from Wolf-Rayet stars.
A Wolf-Rayet star is born as an O-type star with more than 25 times the mass of the Sun, and is very likely to become a black hole after it collapses in its final stage of evolution.
It burns hotter than when it was a young star, causing a stellar wind that spews enormous amounts of gas into space.
The gas emitted by the Wolf-Raye star becomes dust, just like the process of flour turning into bread, so the conditions and ingredients must be right.
Hydrogen, which is the most common in stars, cannot form cosmic dust alone, but Wolf-Rayet stars lose a lot of mass and then eject heavy elements such as carbon deep inside the star.
These elements are blown out into space and cooled, where they meet the stellar winds of other stars, where they are compressed enough to become dust.
Some of the Wolf-Rayet stars use this process to create dust, but that doesn’t mean they create rings of dust similar to tree rings like WR-140.
The dust ring of WR-140 was formed because the Wolf-Rayet star has an elongated elliptical orbit and approaches its companion at a period of 7.93 years, reflecting the passage of time, the team explained.
If the Webb telescope had been more powerful, it was suggested that more than 17 dust rings could be found.
The research team analyzed that the stellar winds of the WR-140 binary system cleanly swept away the material that could have collided with it, so that the dust rings were not scattered or their shape was crushed.
The team called the dust ring a ‘shell’, saying it was thicker and wider than the Webb telescope image shows.
The research team also said that there is evidence that the sun was created through this scenario, saying that material pushed out by the stellar winds of Wolf-Rayet stars can play an important role in forming new stars as they accumulate and become denser on the outer edge.
“While Wolf-Rayet stars are rare in our galaxy (only about 600 can be identified), they may have created a lot of dust before they exploded to form a black hole,” said Patrick Morris, an astrophysicist at the California Institute of Technology and co-author of the paper. “I think the Webb telescope will teach us a lot about how these stars make matter between the stars and trigger new star formation.”
/yunhap news