文章来源:未知 文章作者:enread 发布时间:2011-06-30 01:29 字体: [ ]  进入论坛

Newton space observatory1 has watched a faint star flare2 up at X-ray wavelengths3 to almost 10 000 times its normal brightness. Astronomers4 believe the outburst was caused by the star trying to eat a giant clump5 of matter. The flare took place on a neutron6 star, the collapsed7 heart of a once much larger star. Now about 10 km in diameter, the neutron star is so dense8 that it generates a strong gravitational field.

The clump of matter was much larger than the neutron star and came from its enormous blue supergiant companion star.

"This was a huge bullet of gas that the star shot out, and it hit the neutron star allowing us to see it," says Enrico Bozzo, ISDC Data Centre for Astrophysics, University of Geneva, Switzerland, and team leader of this research.

The flare lasted four hours and the X-rays came from the gas in the clump as it was heated to millions of degrees while being pulled into the neutron star's intense gravity field. In fact, the clump was so big that not much of it hit the neutron star. Yet, if the neutron star had not been in its path, this clump would probably have disappeared into space without trace.

XMM-Newton caught the flare during a scheduled 12.5-hour observation of the system, which is known only by its catalogue number IGR J18410-0535, but the astronomers were unaware9 of their catch immediately.

The telescope works through a sequence of observations carefully planned to make the best use of the space observatory's time, then sends the data to Earth.

It was about ten days after the observation that Dr Bozzo and his colleagues received the data and quickly realised they had something special. Not only were they pointing in the right direction to see the flare, but the observation had lasted long enough for them to see it from beginning to end.

"I don't know if there is any way to measure luck, but we were extremely lucky," says Dr Bozzo. He estimates that an X-ray flare of this magnitude can be expected a few times a year at the most for this particular star system.

The duration of the flare allowed them to estimate the size of the clump. It was much larger than the star, probably 16 million km across, or about 100 billion times the volume of the Moon. Yet, according to the estimate made from the flare's brightness, the clump contained only one-thousandth of our natural satellite's mass.

These figures will help astronomers understand the behaviour of the blue supergiant and the way it emits matter into space. All stars expel(驱逐,开除) atoms into space, creating a stellar wind. The X-ray flare shows that this particular blue supergiant does it in a clumpy fashion, and the estimated size and mass of the cloud allow constraints10(约束) to be placed on the process.

"This remarkable11 result highlights XMM-Newton's unique capabilities," comments Norbert Schartel, XMM-Newton Project Scientist. "Its observations indicate that these flares12 can be linked to the neutron star attempting to ingest a giant clump of matter."


1 observatory hRgzP     
  • Guy's house was close to the observatory.盖伊的房子离天文台很近。
  • Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。
2 flare LgQz9     
  • The match gave a flare.火柴发出闪光。
  • You need not flare up merely because I mentioned your work.你大可不必因为我提到你的工作就动怒。
3 wavelengths 55c7c1db2849f4af018e7824d42c3ff2     
n.波长( wavelength的名词复数 );具有相同的/不同的思路;合拍;不合拍
  • I find him difficult to talk to—we're 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
4 astronomers 569155f16962e086bd7de77deceefcbd     
n.天文学者,天文学家( astronomer的名词复数 )
  • 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》
5 clump xXfzH     
  • A stream meandered gently through a clump of trees.一条小溪从树丛中蜿蜒穿过。
  • It was as if he had hacked with his thick boots at a clump of bluebells.仿佛他用自己的厚靴子无情地践踏了一丛野风信子。
6 neutron neutron     
  • Neutron is neutral and slightly heavier than the proton.中子是中性的,比质子略重。
  • Based on the neutron energy,the value of weighting factor was given.根据中子能量给出了相应的辐射权重因子的数值。
7 collapsed cwWzSG     
  • Jack collapsed in agony on the floor. 杰克十分痛苦地瘫倒在地板上。
  • The roof collapsed under the weight of snow. 房顶在雪的重压下突然坍塌下来。
8 dense aONzX     
  • The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
  • The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。
9 unaware Pl6w0     
  • They were unaware that war was near. 他们不知道战争即将爆发。
  • I was unaware of the man's presence. 我没有察觉到那人在场。
10 constraints d178923285d63e9968956a0a4758267e     
强制( constraint的名词复数 ); 限制; 约束
  • Data and constraints can easily be changed to test theories. 信息库中的数据和限制条件可以轻易地改变以检验假设。 来自英汉非文学 - 科学史
  • What are the constraints that each of these imply for any design? 这每种产品的要求和约束对于设计意味着什么? 来自About Face 3交互设计精髓
11 remarkable 8Vbx6     
  • She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
  • These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。
12 flares 2c4a86d21d1a57023e2985339a79f9e2     
n.喇叭裤v.(使)闪耀( flare的第三人称单数 );(使)(船舷)外倾;(使)鼻孔张大;(使)(衣裙、酒杯等)呈喇叭形展开
  • The side of a ship flares from the keel to the deck. 船舷从龙骨向甲板外倾。 来自《简明英汉词典》
  • He's got a fiery temper and flares up at the slightest provocation. 他是火爆性子,一点就着。 来自《现代汉英综合大词典》
TAG标签: space star neutron