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托福听力练习-科学美国人60秒:白矮双星合并计划

2017-03-31 16:24:00来源：科学美国人60秒

点击查看>>科学美国人60秒音频：白矮双星合并计划

　　科学美国人60秒听力练习：白矮双星合并计划

　　科学美国人60秒英文文本

　　Just like corporations, stars, too, can engage in mergers and acquisitions: a new study has identified a pair of white dwarf stars heading toward a merger.

　　White dwarfs are the hot, superdense remnants of spent stars. In a binary system called J0651, two white dwarfs circle each other very rapidly. The binary pairing completes an orbit in less than 13 minutes.

　　And that already rapid orbital dance is speeding up as the two white dwarfs spiral in on each other. Each year their orbital period shrinks by 0.3 milliseconds. That's actually a pretty dramatic change on astronomical timescales.

　　In about a million years, the white dwarfs will get so close that the larger one will start to cannibalize its smaller companion. Before long, the two stars will likely become one. The study appears in the Astrophysical Journal Letters.

　　The tightly wound white dwarf binary should also be radiating gravitational waves—ripples in the fabric of space and time. But today's gravitational wave detectors are not sensitive enough to detect them. That's okay—astronomers have another million years, before things get really interesting, to build an instrument that's up to the task.

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本文关键字: 托福听力 科学美国人

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