Latest news with #planetarysystem
Reuters
2 days ago
- Science
- Reuters
Webb telescope spots infant planets in different stages of development
WASHINGTON, June 12 (Reuters) - The James Webb Space Telescope has observed two large planets at different stages of infancy - one with an atmosphere brimming with dusty clouds and the other encircled by a disk of material - orbiting a young sun-like star in a discovery that illustrates the complex nature of how planetary systems develop. The two gas giant planets, both more massive than our solar system's largest planet Jupiter, were directly imaged by Webb in a planetary system located in the Milky Way galaxy about 310 light years from Earth in the direction of the constellation Musca. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). Astronomers have detected more than 5,900 planets beyond our solar system - called exoplanets - since the 1990s, with less than 2% of these directly imaged like these two. It is rare to find exoplanets in their early developmental stages. The birth of a planetary system begins with a large cloud of gas and dust - called a molecular cloud - that collapses under its own gravity to form a central star. Leftover material spinning around the star in what is called a protoplanetary disk forms planets. This planetary system was observed by Webb very early in its developmental history. The star, named YSES-1, is about the same mass as the sun. The two planets orbit a long distance from the star, each probably needing thousands of years to complete a single orbit. While the sun is roughly 4.5 billion years old, this star is approximately 16 million years old, a veritable newborn. The researchers were surprised to find that the two neonatal planets observed by Webb appeared to be at different stages of development. The innermost of the two has a mass about 14 times greater than Jupiter and orbits the star at a distance 160 times greater than Earth orbits the sun and more than five times as far as our solar system's outermost planet Neptune. The planet is surrounded by a disk of small-grained dust, a state one might expect in a very early stage of formation when it is still coalescing, or perhaps if there has been a collision of some kind or a moon is in the process of taking shape. Webb spotted water and carbon monoxide in its atmosphere. The outermost planet has a mass about six times greater than that of Jupiter and orbits the star at 320 times the distance of Earth to the sun. Its atmosphere is loaded with silicate clouds, differing from our solar system's gas giants. Webb also detected methane, water, carbon monoxide and carbon dioxide in the atmosphere. It has no disk of material around it. The puzzling combination of traits presented by these two planets in the same system illustrates "the complex landscape that is planet formation and shows how much we truly don't know about how planetary systems came to be, including our own," said astrophysicist Kielan Hoch of the Space Telescope Science Institute in Baltimore, who led the study published this week in the journal Nature, opens new tab. "Theoretically, the planets should be forming around the same time, as planet formation happens fairly quickly, within about one million years," Hoch said. A real mystery is the location where the planets formed, Hoch added, noting that their orbital distance from the host star is greater than would be expected if they formed in the protoplanetary disk. "Furthermore, why one planet still retains material around it and one has distinct silicate clouds remains a big question. Do we expect all giant planets to form the same way and look the same if they formed in the same environment? These are questions we have been investigating for ages to place the formation of our own solar system into context," Hoch said. In addition to amassing a trove of discoveries about the early universe since becoming operational in 2022, Webb has made a major contribution to the study of exoplanets with its observations at near- and mid-infrared wavelengths. "Webb is revealing all sorts of atmospheric physics and chemistry happening in exoplanets that we didn't know before, and is currently challenging every atmospheric model we used pre-Webb," Hoch said.
The Guardian
4 days ago
- Science
- The Guardian
Astronomers left puzzled by high-altitude clouds forming on young planet
Should humans ever venture to a particular planet that circles a sun-like star in the constellation of the fly, they would do well to keep an eye on the weather. The thick slabs of cloud that blot the planet's skies are mostly made from mineral dust, but astronomers suspect there may be iron in them, too, which would rain down on the world below when the clouds break. Astronomers spotted the high-altitude clouds when they trained the James Webb space telescope (JWST) on the young star system, which lies 307 light years away in the deep southern sky. The star, YSES-1, is a newbie by cosmic standards, a mere 1m years old compared with the 4.6bn-year-old sun. The star is circled by two gas giants, both still forming and both larger than Jupiter, the biggest planet in the solar system. Dr Kielan Hoch, an astrophysicist at the Space Telescope Science Institute in Baltimore, Maryland, said the planetary system's youth made it a prime target for astronomers to learn more about the early evolution of planets around faraway stars. 'There's a small handful of multiplanet systems that have been directly imaged,' Hoch said. 'And they are a unique laboratory to test planet formation theories as they formed in the same environment.' 'Both planets are still forming, which is why they are still bright enough for us to detect,' she added. 'The light we are seeing is from their formation as they begin to shrink and condense.' When the team began their observations they were surprised to find both planets in the telescope's field of view, giving them information on two worlds for the price of one. The outer planet, YSES-1c, is the smaller of the two worlds, and about six times the mass of Jupiter. The telescope revealed high-altitude clouds in the planet's atmosphere, but instead of being made from water vapour as on Earth, the clouds consist of magnesium silicate dust grains and perhaps some iron. 'The iron would indeed precipitate out,' Hoch said. The astronomers described the observations as the first direct detection of such clouds on a planet circling a sun-like star. Further data revealed a disc of material made up of trillions of tonnes of dust particles around the larger inner world, YSES-1b, about 14 times the mass of Jupiter. The findings were published in Nature. Hoch said the disc around the inner planet was a 'puzzle for formation theories' since both planets must have formed in the same environment. 'Why did YSES-1b hold on to material around it while YSES-1c did not?' she said. An added mystery is why a 16m-year-old planet still has a disk of material swirling around it. Astronomers' theories of planet formation suggest that any encircling dust should have settled after the first 5m years. 'We wouldn't expect the planets to look so different from one another if they formed in the same protoplanetary disk,' Hoch said. 'JWST is providing an immense amount of data to continue to refine models and improve our understanding.' The $10bn telescope has transformed astronomy since it launched in December 2021 from Europe's Spaceport in French Guiana. The flagship mission has peered back to the first galaxies that lit up the cosmos, spied strange new worlds, and witnessed black holes colliding. It has even spotted tantalising, if controversial, hints of life beyond Earth.
