\u201cNow we have both, the gas and the dust,\u201d said Professor Ilaria Pascucci. \u201cObserving the gas is much more difficult because it takes much more observing time, and that\u2019s why we have to go for a large program like this one to obtain a statistically significant sample.\u201d<\/p>\n A close look at planet-forming disks<\/p>\n AGE-PRO examined 30 disks around Sun-like stars<\/a> in three star-forming regions that span one to six million years in age. <\/p>\n These disks were studied not only for their dust properties, as in previous research, but also for their gas mass and size \u2013 providing the first robust look at how gas content evolves throughout a disk\u2019s lifetime.<\/p>\n The most surprising result of the study was that gas and dust do not vanish together. Large amounts of gas blow away early, then leak more slowly as the disk grows older. Dust, however, tends to persist.<\/p>\n The researchers also found that the gas-to-dust mass ratio evolves over time \u2013 and not necessarily in the way earlier models predicted. <\/p>\n Smaller disks weren\u2019t shedding their gas faster, as previously assumed. Instead, the gas-to-dust ratio appeared surprisingly consistent across disks of different sizes, a twist that hints at deeper complexities in disk evolution.<\/p>\n What this means for planet birth<\/p>\n If gas leaves early, giant planets like Jupiter must form rapidly before the disk\u2019s supply runs out. Rocky planets<\/a>, by contrast, may continue building over a longer timeline, supported by lingering dust.<\/p>\n Ke Zhang of Wisconsin-Madison, principal investigator of AGE-PRO, noted that some older disks still carry more gas than expected. This unexpected retention suggests a wider variety of evolutionary paths \u2013 and potentially more diverse planetary systems \u2013 than previously assumed.<\/p>\n The disk\u2019s initial mass, size, and angular momentum also influence the types of planets it can form \u2013 whether gas giants, icy giants, or mini-Neptunes<\/a> \u2013 as well as their migration patterns after formation.<\/p>\n Finding the faintest signals<\/p>\n ALMA\u2019s sharp vision enabled the team to detect faint \u201cfingerprints\u201d of cold gas in the form of molecular spectral lines. <\/p>\n While carbon monoxide (CO) is the most commonly used gas tracer, AGE-PRO went further \u2013 adding diazenylium, formaldehyde, methyl cyanide, and even molecular species containing deuterium, a rare hydrogen isotope. These additional tracers significantly improved the accuracy of gas mass estimates.<\/p>\n This marks the first large-scale chemical survey of planet-forming disks across multiple evolutionary stages, made possible by ALMA\u2019s sensitivity and long integration times.<\/p>\n Eyes on planet-forming regions<\/p>\n The researchers focused on three nearby regions where stars and planets are currently forming: Ophiuchus, Lupus, and Upper Scorpius. <\/p>\n These regions represent different stages in the evolution of protoplanetary disks \u2013 with Ophiuchus being the youngest (around 1 million years old).<\/p>\n Lupus is in the middle (1\u20133 million years), and Upper Scorpius is the oldest (about 5\u20136 million years). This range allowed the team to observe how gas and dust behave over time as disks age.<\/p>\n Radio signals and planet-forming disks <\/p>\n Dingshan Deng, a graduate student at the University of Arizona\u2019s Lunar and Planetary Laboratory, handled the painstaking data reduction for the Lupus region. <\/p>\n The task involved turning raw radio signals<\/a> into detailed images of the disks, a step essential for measuring gas mass.<\/p>\n \u201cThanks to these new and long observations, we now have the ability to estimate and trace the gas masses, not only for the brightest and better studied disks in that region, but also the smaller and fainter ones,\u201d said Deng. <\/p>\n \u201cThanks to the discovery of gas tracers in many disks where it hadn\u2019t been seen before, we now have a well-studied sample covering a wide range of disk masses in the Lupus star-forming region.\u201d<\/p>\n A legacy for future work<\/p>\n According to Professor Pascucci, it took years to figure out the proper data reduction approach and analysis to produce the images used in this paper for the gas masses and in many other papers of the collaboration.<\/p>\n The AGE-PRO data create a public spectral-line library covering key stages of disk evolution. Astronomers worldwide can now compare young and old disks using the same observational foundation. <\/p>\n The team hopes this resource will fuel new models of planet formation<\/a>, offering insights into how worlds emerge and migrate inside their dusty cradles.<\/p>\n The full study was published in the journal The Astrophysical Journal<\/a>.<\/p>\n Image Credit: NSF\/AUI\/NSF NRAO\/S.Dagnello<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/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":"Planet formation begins around young stars, inside swirling disks of gas and dust. A new analysis of data…\n","protected":false},"author":2,"featured_media":189069,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3844],"tags":[70,413,16,15],"class_list":{"0":"post-189068","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-science","9":"tag-space","10":"tag-uk","11":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114693258860476939","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/189068","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=189068"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/189068\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/189069"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=189068"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=189068"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=189068"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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\n<\/a><\/p>\n