Brown dwarfs are balls of warm gas that lack the mass necessary to fuse hydrogen at their core, as stars can.

棕矮星是一些由炽热的气体组成的球，它们缺乏像行星那样足够的质量来进行氢的燃烧。

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The core could be very, very rich in hydrogen (a water ingredient) or totally dry.

地核中可能有巨量的氢（水分子的一种组分）或者完全干燥。

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The authors analysed 340,000 years of oxygen and hydrogen isotope data from three ice core sites across East Antarctica, alongside isotope-enabled general circulation model results.

科学家们分析了340，000年的横跨东南极洲的三个冰芯地址的氢氧同位素数据，并与同位素启用整体循环模式系统得出的结果。

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Red giants are created when a star exhausts its supply of hydrogen at its core, with the result that the inner layer contracts and the outer layers expand, forming a redder and much larger star.

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This architecture also enables NASA to leverage existing capabilities and lower development costs by using liquid hydrogen and liquid oxygen for both the core and upper stages.

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Dr Marcy suspects that his new discovery, which has about 45 times the mass of the Earth, is composed of a rocky core surrounded by a thick envelope of hydrogen and helium gas.

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