For the first time, researchers have photographed winds from an ancient planet-forming disk that was actively dispersing its gas content. The James Webb Space Telescope (JWST) is helping scientists understand how planets form by improving our understanding of the birthplaces of planets and the circumstellar disks surrounding young stars.

In the article published in Astronomy MagazineLed by Naman Bajai from the University of Arizona and Dr. A team of scientists, including Uma Gorty, captured wind from an ancient planet-forming disk (still very young relative to the Sun) for the first time. actively disperses gas content. The disk has been imaged before, not winds from older disks. Knowing when the gas will dissipate is important because it limits the amount of time newly formed planets have to consume gas from their surroundings.

Central to this discovery is the observation of TCha, a young star (relative to the Sun) surrounded by an abrasion disk known for its large dust gap of about 30 AU in radius. Astronomers have imaged emitted gas (aka winds) for the first time using four lines of noble gases neon (Ne) and argon (Ar); one of these is the first detection of a planet-forming disk. Picture [Ne II] Show that the wind originates from the expanding region of the disk. The team, members of the JWST program led by Ilaria Pascucci (U Arizona), are also interested in how this process occurs so they can better understand its history and impact on our solar system.

“These winds can be driven either by high-energy stellar photons (light from the star) or by the magnetic field that knits together the planet-forming disk,” Naman said.

Uma Horthy of the SETI Institute has been studying disk scattering for decades and, together with a colleague, predicted the strong argon emission detected by JWST. She herself is “thrilled to finally be able to unravel the physical conditions of wind to understand how they are triggered.”

Evolution of planetary systems

Planetary systems such as our Solar System appear to contain more rocky objects than gas-rich ones. Around our Sun are the inner planets, the asteroid belt and the Kuiper belt. But scientists have long known that the planet-forming disks initially had 100 times more mass of gases than solids; This raises an urgent question: When and how does most of the gas leave the disk/system?

In the very early stages of planetary system formation, planets coalesce into a disk of gas and small dust orbiting a young star. These particles stick together to form increasingly larger pieces called planetoids. Over time, these planetoids collide and stick together to form planets. The type, size and location of planets formed depend on the amount of material present and how long it remains in the disk. The outcome of planet formation therefore depends on the evolution and propagation of the disk.

The same group, Dr. Another paper, led by Andrew Selleck, modeled the scattering caused by stellar photons to be able to distinguish between them. They compare these simulations with actual observations and find that scattering of high-energy stellar photons can explain the observations and thus cannot be ruled out as a possibility. Andrew explained that “measuring all four lines simultaneously with the JWST proved how important it is in determining the properties of the wind and helped us show that a significant amount of gas was dispersed.” To put this into context, researchers calculated that the mass emitted each year is equivalent to the mass of the Moon! In the attached document currently under review Astronomy MagazineThese results will be explained in detail.

Transformational discoveries and future prospects

Liner [Ne II] first detected in 2007 by the Spitzer Space Telescope in the direction of several planet-forming disks and soon identified as a wind tracer by project leader Professor Pascucci of the University of Arizona; this transformed the research effort focused on understanding the distribution of disk gas. Discovery [Ne II] with spatial resolution and initial detection [Ar III] JWST may be the next step in transforming our understanding of this process.

“We first used neon to study planet-forming disks more than a decade ago, testing our computational simulations against Spitzer data and new observations from the ESO VLT,” said Professor Richard Alexander from the University of Leicester’s School of Physics. Astronomy. We learned a lot, but these observations did not allow us to measure how much mass the disks lost. The new JWST data is impressive and I never thought it would be possible to distinguish disk rotations in the images. “With more observations like this coming, JWST will allow us to understand young planetary systems like never before.”

Additionally, the team found that T Cha’s inner disk evolved over very short time periods of decades; They found that the JWST T Cha spectrum was different from the previous Spitzer spectrum. According to Chenyang Xie of the University of Arizona, lead author of this ongoing study, this discrepancy can only be explained by a small, asymmetrical inner disk that loses some of its mass over ~17 years. Along with other studies, this indicates that the T Cha disk has reached the end of its evolution. Chengyang adds: “We may witness the entire mass of dust in T Cha’s inner disk dispersed within our lifetime!”

The results of these discoveries provide new insights into the complex interactions that lead to the emission of gas and dust critical to planet formation. By understanding the mechanisms behind disk scattering, scientists can better predict suitable timelines and environments for planet birth. The team’s work demonstrates the power of JWST and opens a new way to study the dynamics of planet formation and the evolution of circumstellar disks.