{"id":794938,"date":"2025-04-03T05:39:03","date_gmt":"2025-04-03T10:39:03","guid":{"rendered":"http:\/\/spaceweekly.com\/?p=794938"},"modified":"2025-04-03T05:39:03","modified_gmt":"2025-04-03T10:39:03","slug":"birthplaces-of-new-planets-come-in-many-different-sizes","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=794938","title":{"rendered":"Birthplaces of new planets come in many different sizes"},"content":{"rendered":"


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View larger. | These are the 73 protoplanetary disks \u2013 or planet-forming disks \u2013 that ALMA observed in the Lupus region (2 of the images contain binary stars). New research shows that such disks \u2013 the birthplaces of new planets \u2013 come in a much wider range of sizes than previously thought. The size of Neptune\u2019s orbit is shown at the bottom right for scale. AU means astronomical unit. One AU is the average distance from the sun to Earth. Image via Guerra-Alvarado et al.\/ Astronomie.nl.<\/figcaption><\/figure>\n
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  • Protoplanetary disks are huge rotating disks of gas and dust<\/strong> around newborn stars. They are the birthplaces of new planets.<\/li>\n
  • Astronomers had thought almost all protoplanetary disks are big,<\/strong> about the size of our solar system or larger. But new observations show they come in a wide range of sizes.<\/li>\n
  • About 2\/3 of protoplanetary disks are much smaller than first thought.<\/strong> They tend to form around young red dwarf stars and also lack the gaps seen in larger disks, where giant planets form. This means our own solar system\u2019s original disk was not typical of most stars.<\/li>\n<\/ul>\n

    What is a typical protoplanetary disk?<\/h3>\n

    Planets are born in disks of dust and gas around newborn stars called protoplanetary disks. Many of those disks are immense, as large as our solar system or more. In fact, astronomers had thought that most, if not nearly all, such disks are this size. But a team of international astronomers said on March 26, 2025, that they\u2019ve used the Atacama Large Millimeter\/submillimeter Array (ALMA) to take a closer look at 73 protoplanetary disks in the Lupus star-forming region. And they found about 2\/3 of those disks are much smaller than first thought. Unlike larger disks, the smaller ones don\u2019t have gaps or rings. So what is<\/em> a typical protoplanetary disk? Or is there no such thing?<\/p>\n

    The researchers\u2019 new paper has been accepted for publication in Astronomy & Astrophysics<\/em>. You can read a preprint version on arXiv submitted on March 25, 2025.<\/p>\n

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    The birthplaces of new planets<\/h3>\n

    Planet-forming disks \u2013 or protoplanetary disks<\/em> \u2013 are huge swirling disks of dust and gas around young stars. They are the birthplaces of new planets. Astronomers have imaged hundreds of them in recent years. How big are they? Until now, most of the disks that astronomers found have been enormous. If centered around our sun, they would extend past the orbit of Neptune.<\/p>\n

    Astronomers thought these were typical for protoplanetary disks. But that seems not to be the case after all.<\/p>\n