Title: The Striking Image of a Dying Star with a 'Shell' Revealed
The James Webb Space Telescope has unveiled a mesmerizing photograph of Wolf-Rayet 140, a dual star system within our galaxy, adorned with concentric bands of cosmic debris. This stellar system, located about 5,000 light-years from Earth, bears a striking resemblance to a tree's cross-section on a colossal scale.
The image, recently published in The Astrophysical Journal Letters, signified the rings' existence and offered clues regarding the dispersal of elements such as carbon throughout the cosmos. A team of astronomers investigated the Webb images, leading to their findings presented at the 245th meeting of the American Astronomical Society in National Harbor, Maryland.
Emma Lieb, a researcher at the University of Denver and the study's lead author, described the Webb's impact in a NASA press release, stating, "The telescope not only confirmed that these dust shells are real, its data also showed that the dust shells are moving outward at consistent velocities, revealing visible changes over incredibly short periods of time."
Wolf-Rayet stars teeter on the brink of supernova explosions. Typically larger than the Sun, these stars are rapidly shedding mass as they reach the end of their existence. Once they expire, they eject their material into space in a spectacular supernova. However, only one of the stars in the WR 140 system falls under this category, being roughly 10 times as massive as the Sun.
In 2023, the Webb Space Telescope captured an awe-inspiring view of WR 124, a star 30 times the mass of the Sun located around 15,000 light-years away. Streams of gas and dust are emanating away from the system's central star at a mind-boggling 93,200 miles per hour (150,000 kilometers per hour).
WR 140 has expelled more than 17 dust shells into the cosmos in the past 130 years. The system's oldest shells have dissipated so much that they are no longer detectable.
In contrast, the shells surrounding WR 140 are expanding at a rate of over 1,600 miles per second (2,600 kilometers per second). This rapid expansion has allowed the dust to disperse into the surrounding space at unprecedented speeds.
An animation demonstrates how the dust shells originate from interactions between the two stars at the system's core. The stars' winds collide, compressing the material into carbon-rich dust, which is subsequently launched into space.
The dust formation process occurs around every eight-year orbit the stars make; hence, the tree ring metaphor extends even further. Each visible ring in the image signifies one orbital period for the system.
WR 140 in mid-infrared light. Image: NASA, ESA, CSA, STScI; Science: Emma Lieb (University of Denver), Ryan Lau (NSF NOIRLab), Jennifer Hoffman (University of Denver)
The Webb Space Telescope captured the two mid-infrared images above in July 2022 (left) and September 2023 (center). The inset image (right) shows how the dust shells have expanded remarkably in just 14 months.
"Mid-infrared observations are indispensable for this analysis since the dust in this system is relatively cool. Near-infrared and visible light would only expose the shells nearest to the star," said study co-author Ryan Lau, an astronomer at NSF's NOIRLab, in the same release. "With these detailed insights, the telescope also aids us in understanding the exact days when the stars are forming dust."
Although the exact timeline for the Wolf-Rayet star's demise remains unclear, the Webb Space Telescope has proven to be a valuable tool for observing how this vital distributor of carbon-rich material spreads its product across space.
The discovery of the expanding dust shells around WR 140 indicates exciting possibilities for future space exploration and technology. With advanced telescopes like the Webb, scientists can observe the dispersal of elements like carbon throughout the universe, providing insights into the life cycles of stars and the evolution of galaxies.
Furthermore, the study of dual star systems like WR 140 could pave the way for future breakthroughs in space science and technology, offering an opportunity to better understand the intricacies of stellar interactions and the role of massive stars in the universe's cosmic balance.
