NASA’s James Webb Telescope Reveals New Insights into Carbon-Rich Dust Formation in the Milky Way.

 

Two mid-infrared images from NASA’s James Webb Space Telescope reveal carbon-rich dust moving at nearly 1% the speed of light in the Wolf-Rayet 140 system, located 5,000 light-years away in the Milky Way, with significant changes observed over 14 months.

Astronomers have long sought to understand how essential elements like carbon spread across the universe. Now, NASA’s James Webb Space Telescope has provided groundbreaking observations of one source of carbon-rich dust in our galaxy. The telescope recently observed Wolf-Rayet 140, a binary star system where two massive stars follow an elongated orbit. As these stars swing past one another, their stellar winds collide, compressing material and creating carbon-rich dust.

Webb’s detailed observations reveal 17 distinct dust shells expanding into space. These shells, visible in mid-infrared light, move outward at speeds exceeding 1,600 miles per second (2,600 kilometers per second)—almost 1% the speed of light. Emma Lieb, a doctoral student at the University of Denver and lead author of the study, highlighted the short timescale of the changes, saying, “The dust shells are expanding from one year to the next.”

Observations of Wolf–Rayet 140 fade between 2022 and 2023.

This video shows two mid-infrared observations from NASA’s James Webb Space Telescope of Wolf-Rayet 140, revealing how the system's dust has expanded over just 14 months, with more than 17 dust shells formed over 130 years.

The system generates these dust shells in cycles, with dust forming during the stars’ closest approaches, roughly every eight years. Webb’s mid-infrared imaging is key to studying these shells, as the dust is cool and would not be visible in visible or near-infrared light. The telescope’s observations allowed researchers to track the precise timing of the dust formation.

While some of the shells have been around for over 130 years, others are newly formed. The dust, which is primarily carbon-rich, varies in distribution. Some areas show dense, amorphous clouds the size of our solar system, while other particles float freely. Regardless, all the dust moves at the same velocity.

Looking toward the future, the fate of the Wolf-Rayet stars remains uncertain. The more massive of the two stars, 10 times the mass of the Sun, is nearing the end of its life and could either explode as a supernova or collapse into a black hole. Researchers hope for the latter, as it could preserve the dust, helping to answer the broader question of where the universe’s dust comes from. The carbon-rich dust plays a crucial role in the formation of rocky planets and solar systems like our own.

These findings, published in The Astrophysical Journal Letters and presented at the 245th American Astronomical Society meeting, highlight the James Webb Space Telescope’s ability to unlock new mysteries about the universe’s most essential elements.

The James Webb Space Telescope is an international collaboration led by NASA, in partnership with the European Space Agency (ESA) and the Canadian Space Agency (CSA). Webb is set to continue unraveling the mysteries of our solar system, distant exoplanets, and the broader cosmos.