JWST captures the end of planet formation (2024)

The James Webb Space Telescope (JWST) has provided groundbreaking insights into the formation of planetary systems. A recent study led by Naman Bajaj at the University of Arizona, utilizing JWST observations, sheds light on the crucial process of gas dispersal in young planetary systems. This exploration offers valuable clues into the evolution of celestial bodies and provides a deeper understanding of our own solar system's development.

JWST captures the end of planet formation (2024)


When a star forms, there's usually a swirling cloud of gas and dust around it. From this cloud, planets start to form. A recent study from the University of Arizona helps us understand how long this process takes in our own solar system.

Scientists think that in systems like ours with planets, there are more solid rocky objects than ones made mostly of gas. In our solar system, these include the inner planets (Mercury, Venus, Earth, and Mars), the asteroid belt, and icy objects in the Kuiper belt, like Pluto.

Jupiter, Saturn, Uranus, and Neptune, however, are mostly made of gas. Scientists have long known that the disks from which planets form begin with 100 times more gas than solid material. This raises an important question: How and when does most of this gas disappear from a developing planetary system?

A recent study led by Naman Bajaj at the University of Arizona looked at a young planetary system using a powerful telescope called the James Webb Space Telescope (JWST). They took pictures of a young planetary system that's still forming, called a circumstellar disk. This disk is losing its gas and spreading it out into space.

Bajaj, a doctoral student at UArizona's Lunar and Planetary Laboratory, explained that figuring out when gas spreads out is crucial. It helps us understand how long gassy planets like Jupiter have to suck up gas from their surroundings. The JWST telescope is giving us amazing views of the disks around young stars, where planets are born. This helps us learn more about how planets come into existence.

In the beginning, when a new solar system forms, there's a big swirling disk of gas and small dust particles around the young star. These tiny bits start sticking together to form bigger pieces called planetesimals. As time goes on, these planetesimals crash into each other and merge, gradually becoming planets. The size, type, and where these planets end up depends on how much stuff is in the disk and how long it sticks around.

"So basically, how planets form depends on how the disk around a star changes over time," Bajaj explained.

Scientists have found something interesting about a young star called T Cha. It's much younger than our sun, which is about 4.6 billion years old. This star has a ring of dust around it, like a hula hoop. But there's a big gap in the ring, about 30 times farther from the star than Earth is from the sun.


JWST


Bajaj and his team used a telescope to take pictures of something called a "disk wind" for the first time. This is gas slowly leaving a disk where planets form. They used the telescope's ability to see the light given off by atoms when they lose electrons because of high-energy radiation, like from stars. This process is called ionization. The light emitted during ionization can show what kind of atoms are present. In the T Cha system, they found two noble gases, neon and argon. The team's observations also found something new double ionization of argon in a planet-forming disk.

"The glowing light we see in our pictures indicates that the wind around the disk is coming from a faraway area, not just the disk itself," explained Bajaj. "These winds might be caused by either the powerful light coming from the star or by the magnetic field that runs through the disk where planets are forming."

A group led by Andrew Sellek from Leiden University in the Netherlands did some computer simulations to see how light from a young star might push the gas away from its surrounding disk. They compared these simulations with what they actually observed and found that the light from the star could be causing the gas to spread out, which means it might be a possible explanation for what they saw. They estimated that the amount of gas leaving the disk each year is about the same as the mass of the Earth's moon. They're planning to publish their findings in a scientific journal called the Astronomical Journal, but it's still being reviewed.

Before 2007, scientists didn't know that neon signatures could come from small disks where planets form. Then, Ilaria Pascucci, a professor, found them using a telescope called Spitzer. She realized they showed how gas moves in these disks. This discovery changed how researchers study how gas leaves these disks. Pascucci is leading the newest project and helping write the reports about it.

Pascucci said, "We found neon and double ionized argon using the James Webb Space Telescope. This could help us learn how gas moves out of disks that form planets. Understanding this could tell us more about how our own solar system formed and evolved."

The group found out that the inner part of T Cha's disk is changing pretty quickly, within decades. When they compared the observations from the James Webb Space Telescope (JWST) to the ones from Spitzer, they noticed differences. Chengyan Xie, a doctoral student at LPL, thinks this difference could be because there's a small, lopsided disk inside T Cha that lost some of its material in the 17 years between the two observations.

Xie said that based on their research and others, it seems like the disk around T Cha is reaching the end of its life. This means we might actually see all the dust around T Cha's inner disk disappear during our lifetime.

The people who helped write the papers are Uma Gorti from the SETI Institute, Richard Alexander from the University of Leicester, Jane Morrison and Andras Gaspar from UArizona's Steward Observatory, Cathie Clarke from the University of Cambridge, Giulia Ballabio from Imperial College London, and Dingshan Deng from the Lunar and Planetary Laboratory.

The information for this study was collected using a special telescope called JWST/MIRI. It was part of a program called General Observers Cycle 1, led by Dr. Ilaria Pascucci. The team involved includes graduate students Naman Bajaj, Chengyan Xie, and Dingshan Deng, along with professors and researchers like Prof. Richard Alexander, Dr. Uma Gorti, and others.

Source

Material is referred from SETI Institute.

Read more
  1. Perihelion and Aphelion: Earth's Dance with the Sun
  2. Nebulae: Cosmic Clouds of Wonder
  3. Wormholes: The Cosmic Gateway to Other Worlds

FAQs 

  1. What is the James Webb Space Telescope?
    The James Webb Space Telescope is a space observatory launched by NASA to study the universe's distant objects and phenomena.

  2. How does JWST differ from other telescopes?
    JWST is equipped with advanced technology that allows it to observe celestial objects with unprecedented clarity and sensitivity.

  3. What are the recent discoveries made by JWST?
    Recent discoveries include observations of the end stages of planet formation within protoplanetary disks surrounding young stars.

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