Wolf Rayet 140 (also known as WR 140 or HD 193793) is a system of two massive stars located approximately 5,000 light-years away in the constellation Cygnus. As these stars swing against each other, the stellar winds from each collide, compressing material and forming carbon-rich dust. New observations from the NASA/ESA/CSA James Webb Space Telescope show that 17 dust shells glowing in the mid-infrared are expanding into the surrounding space at regular intervals.
This image of the carbon-rich Wolf-Rayet star WR 140 was taken by the Webb Mid-Infrared Observer (MIRI) in September 2023. Image credits: NASA / ESA / CSA / STScI / E. Lieb, University of Denver / R. Lau, NSF's NOIRLab / J. Hoffman, University of Denver.
“Webb confirmed that Wolf-Rayet 140's dust shell is real,” said Emma Reeve, a doctoral student at the university. “We have shown that there is a visible change in an incredibly short period of time.” Originally from Denver, Colorado.
“All of the shells are moving away from the star at more than 2,600 kilometers per second, which is almost 1% of the speed of light.”
“We're used to thinking of events in the universe as happening slowly over millions or billions of years,” said Jennifer Hoffman, a professor at the University of Denver.
“In this system, the observatory shows that the dust shell is expanding year by year.”
Dr Olivia Jones, an astronomer at the UK Astronomical Technology Center, said: “It's truly amazing to see the real-time movement of these shells during the Webb observations, which were made just 13 months apart.” Ta.
“These new results provide the first glimpse of the potential role of such giant binary stars as dust factories in the universe.”
Like clockwork, the star's winds generate dust for a few months every eight years. The pair approaches each other in a wide and long orbit.
The web also shows where dust stops forming. Look for the dark area in the top left of the image.
The telescope's mid-infrared images detected shells that have survived for more than 130 years. The old shells have dissipated enough that they are now too dark to detect.
Astronomers estimate that a star will eventually produce tens of thousands of dust shells over hundreds of thousands of years.
“The dust in this system is quite cold, so mid-infrared observations are absolutely critical to this analysis,” said Dr. Ryan Lau, an astronomer at the NSF NOIRLab.
“Near-infrared and visible-light observations only show the shells closest to the star.”
“With these amazing new details…
findings Published in Astrophysics Journal Letter.
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Emma P. Reeve others. 2025. Dynamic signature of dust formation due to wind impact from WR 140. APJL 979, L3; doi: 10.3847/2041-8213/ad9aa9
Source: www.sci.news
