单词	protostar
释义	protostar noun pro·​to·​star ˈprō-tō-ˌstär  : a cloud of gas and dust in space believed to develop into a star Example Sentences Recent Examples on the Web The telescope’s Near-Infrared Spectrograph (NIRSpec) actually captured a protostar in the process of becoming a full-fledged star. Sarah Kuta, Smithsonian Magazine, 7 Sep. 2022 Material falling into the protostar will then begin to interact with its magnetic fields. Elizabeth Gamillo, Smithsonian Magazine, 16 Dec. 2021 Star birth begins with the formation of a protostar as gravity pulls gas clouds together in a process known as accretion. Elizabeth Gamillo, Smithsonian Magazine, 16 Dec. 2021 This creation story begins more than 4.5 billion years ago, when dust and gas from a giant molecular cloud gravitationally collapsed to create a protostar that would become our sun, surrounded by a spinning disk of gas and dust. Jonathan O'callaghan, Scientific American, 8 Dec. 2020 Masses of gas—mostly helium and hydrogen—within these stellar nurseries collapse under their own gravity and begin to heat up, forming a protostar. Jennifer Leman, Popular Mechanics, 13 June 2020 Because the dust in the nebulae obscures them, protostars can be difficult for astronomers to detect. Catherine Zuckerman, National Geographic, 20 Mar. 2019 One of these contracting masses of gas, known as a protostar, represents a star’s nascent phase. Catherine Zuckerman, National Geographic, 20 Mar. 2019 The forming star, or protostar, is about 11,000 light years away, in a much denser and more volatile region of the galaxy. Jay Bennett, Popular Mechanics, 21 Aug. 2016 See More Word History First Known Use 1947, in the meaning defined above
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