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Astronomers1 have discovered the first aurora2 ever seen in an object beyond our Solar System. The aurora - similar to the famous “Northern Lights“ on Earth - is 10,000 times more powerful than any previously3 seen. They found the aurora not from a planet, but from a low-mass star at the boundary between stars and brown dwarfs4. The discovery reveals a major difference between the magnetic activity of more-massive stars and that of brown dwarfs and planets, the scientists said. “All the magnetic activity we see on this object can be explained by powerful auroras,“ said Gregg Hallinan, of the California Institute of Technology (Caltech). “This indicates that auroral5 activity replaces solar-like coronal activity on brown dwarfs and smaller objects,“ he added.The astronomers observed the object, called LSR J1835+3259, using the Karl G. Jansky Very Large Array (VLA) at radio wavelengths6, along with the 5-meter Hale Telescope on Palomar Mountain and the 10-meter Keck Telescope in Hawaii at optical wavelengths. The combination of radio and optical observations showed that the object, 18 light-years from Earth, has characteristics unlike any seen in more- massive stars.Brown dwarfs, sometimes called “failed stars,“ are objects more massive than planets, yet too small to trigger the thermonuclear reactions at their cores that power stars. The astronomers said their observations of LSR J1835+3259 indicate that the coolest stars and brown dwarfs have outer atmospheres that support auroral activity, rather than the type of magnetic activity seen on more-massive and hotter stars.The discovery also has implications for studying extrasolar planets. The aurora the scientists observed from LSR J1835+3259 appears powered by a little-understood dynamo process similar to that seen on larger planets in our Solar System. This process is different from that which causes the Earths auroral displays - the planets magnetic field interacting with the solar wind.词汇解析1 astronomers n.天文学者,天文学家( astronomer 的名词复数 )参考例句:Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自简明英汉词典Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪,为什么只有土星有光环。 来自简明英汉词典2 aurora n.极光参考例句:The aurora is one of natures most awesome spectacles.极光是自然界最可畏的奇观之一。Over the polar regions we should see aurora.在极地高空,我们会看到极光。3 previously adv.以前,先前(地)参考例句:The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。4 dwarfs n.侏儒,矮子(dwarf 的复数形式)vt.(使)显得矮小(dwarf 的第三人称单数形式)参考例句:Shakespeare dwarfs other dramatists. 莎士比亚使其他剧作家相形见绌。 来自简明英汉词典The new building dwarfs all the other buildings in the town. 新大楼使城里所有其他建筑物都显得矮小了。 来自辞典例句5 auroral adj.曙光的;玫瑰色的参考例句:This high result was interpreted to reflect previous aurora activity.这一高结果可以用以前的极光活动来解释。The aurora is one of natures most awesome spectacles.极光是自然界最可畏的奇观之一。6 wavelengths n.波长( wavelength 的名词复数 );具有相同的/不同的思路;合拍;不合拍参考例句:I find him difficult to talk towere on completely different wavelengths. 我没法和他谈话,因为我们俩完全不对路。 来自简明英汉词典Sunlight consists of different wavelengths of radiation. 阳光由几种不同波长的射线组成。 来自辞典例句更多英语学习方法:企业英语培训 http:/www.spiikers.com/
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