The contrast between james webb space telescopeand Spitzer Space Telescope observations just 15 years ago, show changing conditions around a Sun-like star.
in 2008 NASAThe Spitzer Space Telescope has discovered a protoplanetary disk like no other. The dusty disk of gas surrounding the young Sun-like star SZ Chamaeleontis (SZ Cha) is exposed to extreme ultraviolet light previously seen only in computer models and never seen in the real universe. Ta. Planets in this system would take longer to form than in a disk that is vaporized by normal X-rays. But when the James Webb Space Telescope followed up on SZ Cha, it found nothing unusual. There was no abundant ultraviolet radiation. Over a short period of cosmic time, the state of SZ Cha’s disk has changed, forcing astronomers to make sense of the discordant data and uncover the implications for the formation of other solar systems.
Webb Space Telescope tracks neon signs for new ways of thinking about planet formation
Scientists follow neon signs for clues about the future of one planetary system and the past of another, our solar system.follow up unique way of reading NASA’s former flagship infrared observatory, the now-retired Spitzer Space Telescope, allows NASA’s James Webb Space Telescope to detect dust-encrusted objects surrounding the young Sun-like star SZ Chamaeleontis (SZ Cha). We detected clear traces of neon elements within the disc.
The difference in neon measurements between Spitzer and Webb suggests that there is a previously unobserved change in high-energy radiation reaching the disk, which ultimately evaporates it and allows planets to form. Indicates a time limit.
“How did we get here? Which brings us back to that very big question: SZ Cha is a young star of the same type as our Sun at the dawn of our solar system 4.5 billion years ago: a T-Tauri star.” said Boston University astronomer Katherine Espaillat. , in Massachusetts, led both the 2008 Spitzer observations and the just-published new Webb results. of Astrophysics Journal Letter.
“The raw materials for Earth, and ultimately life, existed in the disk of material that surrounded the Sun after it formed. Therefore, studying these other young systems is a challenge for us. “This is the closest we can get to going back in time to find out how the solar system formed. The story begins.”
Neon as a radiation indicator and SZ Cha’s mysterious behavior
Scientists use neon as an indicator of what kind of radiation is hitting and eroding the disk around a star. When Spitzer looked at his SZ Cha in 2008, he saw an outlier with neon measurements that were different from his other young T-shaped Tauri discs. The difference was the detection of Neon III, which is typically rare in protoplanetary disks that are bombarded with high-energy X-rays. This meant that the high-energy radiation in the SZ Cha disk came from ultraviolet (UV) radiation rather than his X-rays. In addition to being the only strange result from a sample of 50 to 60 young stellar disks, the difference between UV and X-rays is important for the lifetime of the disk and its potential planets.
“Planets are essentially racing against the clock to form within the disk before it evaporates,” said Tanaus Tanatibodhi of Boston University, another astronomer on the team. do. “Computer models of the system under development show that extreme ultraviolet light allows planet formation to occur for a million years longer than if evaporation were caused primarily by X-rays.”
So when Espaillat’s team returned to the study with Webb, SZ Cha was already quite the mystery, but they discovered a new surprise. The anomalous Neon III features had all but disappeared, showing the typical dominance of her X-ray emissions.
The researchers believe that the difference in the neon signature of the SZ Cha system is due to the fact that when the wind blows, it absorbs ultraviolet light and leaves behind X-rays that attack the disk. The researchers say that winds are common in systems with newly formed, energetic stars, but it is possible to capture systems during quiet, windless periods, and Spitzer happened to be able to capture them during quiet, windless periods. It is said that this has been realized.
“Both the Spitzer and Webb data are excellent, so we thought this must be something new that we were observing in the SZ Cha system. This is a significant change in the situation in just 15 years.” added co-author Arjan Sturm of Leiden University. ,Netherlands.
Continuing research and the complexity of the universe
Espaillat’s team is already planning further observations with Webb and other telescopes to uncover the mystery. “It will be important to study SZ Cha and other young systems at multiple wavelengths of light, including X-rays and visible light, to discover the true nature of this variability we found.” said co-author Caeley Pittman. Boston University. “Short periods of quiet dominated by extreme ultraviolet light may be common in many young planetary systems, we just haven’t been able to capture them.”
“Again, the universe shows us that none of its methods are as simple as we would like to make them. We must rethink, re-observe, and gather more information.” We need to. We follow the neon signs,” Espaillat said.
The study was published in the journal Nov. 15. Astrophysics Journal Letter.
Reference: “JWST Detects Neon Line Variability in a Protoplanetary Disk” CC Espaillat, T. Thanathibodee, CV Pittman, JA Sturm, MK McClure, N. Calvet, FM Walter, R. Franco-Hernández, J. Muzerolle Page, November. 15th 2023, Astrophysics Journal Letter.
DOI: 10.3847/2041-8213/ad023d
The James Webb Space Telescope is the world’s premier space science observatory. Webb unravels the mysteries of our solar system, looks to distant worlds around other stars, and investigates the mysterious structure and origins of our universe and our place in it. Webb is an international program led by NASA and its partner ESA (european space agency) and the Canadian Space Agency.