The James Webb Space Telescope’s unprecedented infrared resolution revealed three startling things dust belts about a young star nearby, fomalhaut.
The goal was to study the first asteroid belt seen outside our solar system in infrared light. But to their surprise, the dusty structures are much more complex than the asteroid and Kuiper belts in our solar system. In general, there are three overlapping belts extending 23,000 million kilometers from the star, That is 150 times the distance from Earth to the Sun. The outer belt is about twice the scale of the Kuiper Belt of our solar system, the cold dust that resides beyond Neptune. Underbelts, never before seen, were revealed by Webb for the first time.
The belts surround the hot young star, which is visible to the naked eye as the brightest star in the southern constellation Piscis Austrinus. He explains in a statement that dust belts are debris from the collision of large bodies, similar to asteroids and comets, and are often described as “debris disks” to those in our planetary system. Andras Gaspar from the University of Arizona at Tucson and lead author of a new paper describing these findings. “By looking at the patterns in these rings, we can begin to draw a small outline of what a planetary system might look like, if we can image deep enough to see potential planets.”
The Hubble Space Telescope and Herschel Space Observatory, as well as the Atacama Large Millimeter/Submillimeter Array (ALMA), have previously captured sharp images of the outer belt. However, none of them found any structure inside. The inner belts were first resolved by Webb in infrared light. “Where Webb really excels is that we’re able to physically resolve the thermal glow of the dust in those inner regions. So you can see inner belts that we haven’t been able to see before.” Schuyler WolfAnother member of the University of Arizona team.
Hubble, ALMA and Webb are collaborating to piece together a comprehensive view of the debris disks around various stars. “Using Hubble and ALMA, we were able to image a range of Kuiper belt isotopes and learned a lot about how the outer disks form and evolve,” said Wolf. But we need Webb to allow us to image dozens of asteroid belts elsewhere. We can learn as much about the warm inner regions of these disks as Hubble and ALMA have taught us about the cooler outer regions. “
These belts are the most likely Sculpted by the gravitational forces produced by the unseen planets. Similarly, within our solar system, the asteroid belt is surrounded by Jupiter, the inner edge of the Kuiper belt has been carved by Neptune, and the outer edge can be guided by bodies not yet visible. As Webb pictures more systems, we’ll learn about the configurations of their planets.
The Fomalhaut dust ring was discovered in 1983 in observations made by NASA’s Infrared Astronomy Satellite (IRAS). The ring’s existence has also been inferred from previous, longer-wavelength observations using millimeter telescopes on Mauna Kea, Hawaii, NASA’s Spitzer Space Telescope, and the Caltech Subscale Observatory.
“The belts around Fomalhaut are a kind of mystery novel: where are the planets?” He said George Rick, another member of the team and principal US scientist at Webb’s Mid-Infrared Instrument (MIRI), who made these observations. “I think it’s not a huge leap to say there might be a really interesting planetary system around the star.”
“We certainly didn’t expect the more complex structure with the second intermediate belt and then the wider asteroid belt,” Wolf added. “This structure is so exciting because every time an astronomer sees a gap and rings in a disk, he says, ‘There could be an embedded planet that forms the rings!'” “
Webb also captured images of what Jasper calls a “large dust cloud,” which may be evidence of a collision in the outer ring between two protoplanetary bodies. This is a different feature of a hypothesized planet first seen within the outer ring by Hubble in 2008. Subsequent Hubble observations showed that by 2014 the object had disappeared. A reasonable explanation is that this newfound feature, like the one above, is a Expanding cloud of very fine dust particlesTwo frozen bodies collided with each other.
Publish the team’s results in the journal natural astronomy.
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