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NASA’s James Webb Telescope Reveals New Insights on Star and Planet Interaction
Recent observations by NASA’s James Webb Space Telescope have presented unexpected revelations about what was thought to be the first recorded instance of a star consuming a planet. Contrary to previous theories that suggested the star expanded and engulfed the planet, the new findings indicate that instead, the planet’s orbit gradually decreased over time, leading to its eventual destruction.
“Given the uniqueness of this event, we approached it without a clear vision of what we might uncover,” said Ryan Lau, the lead author of the study and an astronomer at the National Science Foundation’s National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona. “The high-resolution infrared capabilities of Webb are providing important insights into the ultimate fates of planetary systems, potentially even our own.”
The study was conducted using two instruments aboard Webb: the Mid-Infrared Instrument (MIRI) and the Near-Infrared Spectrograph (NIRSpec). Through a combination of detailed analysis, researchers were able to reach their conclusions about the star and its surrounding environment.
This intriguing star, situated roughly 12,000 light-years from Earth in the Milky Way galaxy, underwent a significant brightening event known as ZTF SLRN-2020. Originally detected as a brief flash of light by the Zwicky Transient Facility in California, follow-up observations by NASA’s NEOWISE revealed that the star had actually seen an increase in infrared brightness a year earlier, indicating the presence of dust. Initial analyses led scientists to believe that the star was akin to our own Sun, gradually aging into a red giant over a prolonged period.
However, findings from Webb’s MIRI presented a different narrative. The instrument’s advanced sensitivity and spatial resolution enabled researchers to accurately assess emissions from the star and its crowded surroundings. The team discovered that the star was not as luminous as it would have been had it expanded into a red giant, dispelling previous notions of a dramatic engulfing process.
According to researchers, the planet, initially comparable in size to Jupiter, orbited perilously close to the star—within a distance smaller than Mercury’s orbit around the Sun. Over millions of years, its proximity to the star decreased, culminating in a catastrophic fate.
As explained by Morgan MacLeod from the Harvard-Smithsonian Center for Astrophysics and MIT, “Eventually, the planet began to interact with the star’s atmosphere, setting off a swift descent towards the star.” He further noted, “As the planet moved inward, it started to spread around the star.”
Upon its final plunge, the planet would have ejected gas from the star’s outer layers. As the star cooled and expanded in response, heavier elements from this gas formed cold dust over the following year.
The team anticipated observing a cooler dust cloud surrounding the star; however, NIRSpec revealed a hot circumstellar disk of molecular gas closer to the star. The high spectral resolution of Webb also enabled the detection of various molecules, including carbon monoxide, within this accretion disk.
Colette Salyk, an exoplanet researcher at Vassar College and co-author of the study, remarked, “Using a transformative telescope like Webb left me with no clear expectations regarding the immediate surroundings of the star. I certainly did not anticipate finding what appears to be characteristics of a planet-forming region, particularly in the context of post-engulfment.”
This capacity to analyze the gas raises new inquiries regarding the events that followed the planet’s consumption by the star. “We are truly at the forefront of investigating such phenomena. This is the only instance we’ve seen in real-time, and it represents the most comprehensive understanding of the aftermath post-event,” Lau stated. “We hope this is merely the beginning of expanding our sample.”
The observations carried out as part of the Guaranteed Time Observation program 1240 were aimed at exploring a category of enigmatic, sudden infrared brightening occurrences. These studies are integral for events like supernovae, which, while expected, occur unpredictably regarding timing and location. NASA’s space telescopes are part of a growing international initiative prepared to observe these transient events, assisting in unraveling the workings of the universe.
Future surveys conducted by the Vera C. Rubin Observatory and NASA’s Nancy Grace Roman Space Telescope are anticipated to help researchers identify additional occurrences of this nature by repeatedly examining large swathes of the sky for variations.
The findings from this research are detailed in an article published in The Astrophysical Journal.
The James Webb Space Telescope serves as the foremost space science observatory globally, providing insights into our solar system, exploring distant worlds orbiting other stars, and examining the intricate structures and origins of the universe. Webb operates as a collaborative effort led by NASA with contributions from the European Space Agency and the Canadian Space Agency.
For further information about Webb, visit: NASA’s Webb page.
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