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That puts it in a strange spot. It\u2019s big enough to raise doubts about how it formed, yet not quite big enough to clearly belong in another category.<\/p>\n
How planets like 29 Cygni b form<\/p>\n
There are two main ways scientists think objects like this can form. One is the slow, steady buildup inside a disk of gas and dust around a young star. <\/p>\n
This process is called accretion. It\u2019s how Earth formed, and how Jupiter<\/a> likely came together, gathering gas after its core grew large enough.<\/p>\n The other way is faster and more dramatic. A cloud of gas can break apart into chunks, and each chunk collapses under its own gravity. That\u2019s how stars form. <\/p>\n Some scientists think this same kind of breakup could happen in the disks around stars, creating large objects quickly.<\/p>\n Categorizing 29 Cygni b exoplanet<\/p>\n 29 Cygni b sits right on the edge between these two ideas. It\u2019s massive, but not quite massive enough to clearly form like a star. It also orbits at a distance where building a planet through slow growth should be difficult.<\/p>\n That\u2019s why a team led by William Balmer studied it using NASA\u2019s James Webb Space Telescope. They wanted to know which story fits better. <\/p>\n Balmer, who works at Johns Hopkins University and the Space Telescope Science Institute<\/a>, summed up the puzzle clearly: \u201cIn computer models, it\u2019s very easy for fragmentation in a disk to run away to much higher masses than 29 Cygni b.\u201d<\/p>\n \u201cThis is the lowest mass you could plausibly get. But at the same time, it\u2019s about the highest mass you could get from accretion.\u201d<\/p>\n Reading a planet\u2019s chemical fingerprints<\/p>\n To figure this out, the team used Webb\u2019s near-infrared camera to directly image the planet. They looked at how its atmosphere absorbs light, focusing on gases like carbon dioxide and carbon monoxide. <\/p>\n These gases help reveal how many heavy elements, often called metals in astronomy<\/a>, are present.<\/p>\n The results told a clear story. The planet contains a large amount of heavy material, roughly equal to about 150 Earths. That kind of enrichment usually points to a planet that formed by gathering solid material first, then pulling in gas later.<\/p>\n This matters because stars don\u2019t typically show that same pattern. They form mostly from gas, without the heavy buildup of solids.<\/p>\n The importance of alignment<\/p>\n The team didn\u2019t stop at chemistry. They also studied how the planet moves. Using a ground-based telescope array called CHARA, they measured the tilt of the planet\u2019s orbit<\/a> and compared it to the spin of its host star.<\/p>\n They found that the planet\u2019s orbit closely matches the star\u2019s rotation, a pattern often seen in systems that form from a disk.<\/p>\n \u201cWe were able to update the planet\u2019s orbit, and also observed the host star to determine its orientation with respect to that orbit,\u201d said Ash Messier, a graduate student at Johns Hopkins and co-author of the study.<\/p>\n \u201cWe showed that the inclination of the planet is well-aligned with the spin axis of the star, which is similar to what we see for the planets of our solar system<\/a>.\u201d<\/p>\n A clear answer, for now<\/p>\n When the chemical clues and orbital data come together, they point in the same direction. 29 Cygni b likely formed through accretion, even though it pushes that process close to its limits.<\/p>\n \u201cPut together, this evidence strongly suggests that 29 Cygni b formed within a protoplanetary disk through rapid accretion of metal-rich material, rather than through gas fragmentation,\u201d said Balmer. <\/p>\n In other words, it formed like a planet and not like a star<\/a>.<\/p>\n Lessons from 29 Cygni b<\/p>\n This finding fills in an important gap. It shows that even very massive planets can grow through the same bottom-up process that forms smaller worlds. That helps explain how diverse planetary systems can be.<\/p>\n The team is now studying three more objects with similar masses. By comparing them, they hope to see whether smaller and larger giants follow the same rules or start to split into different formation paths.<\/p>\n For now, 29 Cygni b stands as a reminder that nature doesn\u2019t always draw clean lines. Sometimes, the most interesting answers sit right in the middle.<\/p>\n The full study was published in the Astrophysical Journal Letters<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Planets usually start small. Tiny grains of dust and ice bump into each other, stick, and slowly grow.…\n","protected":false},"author":2,"featured_media":408879,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":{"0":"post-408878","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-ie","9":"tag-ireland","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/408878","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=408878"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/408878\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/408879"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=408878"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=408878"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=408878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}