银河系黑洞正吞食小行星
文章来源:未知 文章作者:enread 发布时间:2012-02-13 05:12 字体: [ ]  进入论坛
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The giant black hole at the center of the Milky1 Way may be vaporizing and devouring2(吞食,毁灭) asteroids4, which could explain the frequent flares6 observed, according to astronomers7 using data from NASA's Chandra X-ray Observatory8. For several years Chandra has detected X-ray flares about once a day from the supermassive black hole known as Sagittarius A*, or "Sgr A*" for short. The flares last a few hours with brightness ranging from a few times to nearly one hundred times that of the black hole's regular output. The flares also have been seen in infrared9 data from ESO's Very Large Telescope in Chile.

"People have had doubts about whether asteroid3s(小行星) could form at all in the harsh environment near a supermassive black hole," said Kastytis Zubovas of the University of Leicester in the United Kingdom, and lead author of the report appearing in the Monthly Notices of the Royal Astronomical10 Society. "It's exciting because our study suggests that a huge number of them are needed to produce these flares."

Zubovas and his colleagues suggest there is a cloud around Sgr A* containing trillions of asteroids and comets, stripped from their parent stars. Asteroids passing within about 100 million miles of the black hole, roughly the distance between Earth and the sun, would be torn into pieces by the tidal forces from the black hole.

These fragments then would be vaporized by friction11 as they pass through the hot, thin gas flowing onto Sgr A*, similar to a meteor heating up and glowing as it falls through Earth's atmosphere. A flare5 is produced and the remains12 of the asteroid are swallowed eventually by the black hole.

"An asteroid's orbit can change if it ventures too close to a star or planet near Sgr A*," said co-author Sergei Nayakshin, also of the University of Leicester. "If it's thrown toward the black hole, it's doomed13."



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1 milky JD0xg     
adj.牛奶的,多奶的;乳白色的
参考例句:
  • Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
  • I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。
2 devouring c4424626bb8fc36704aee0e04e904dcf     
吞没( devour的现在分词 ); 耗尽; 津津有味地看; 狼吞虎咽地吃光
参考例句:
  • The hungry boy was devouring his dinner. 那饥饿的孩子狼吞虎咽地吃饭。
  • He is devouring novel after novel. 他一味贪看小说。
3 asteroid uo1yD     
n.小行星;海盘车(动物)
参考例句:
  • Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。
  • It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小,但这样的危险还是存在的。
4 asteroids d02ebba086eb60b6155b94e12649ff84     
n.小行星( asteroid的名词复数 );海盘车,海星
参考例句:
  • Asteroids,also known as "minor planets",are numerous in the outer space. 小行星,亦称为“小型行星”,在外太空中不计其数。
  • Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。
5 flare LgQz9     
v.闪耀,闪烁;n.潮红;突发
参考例句:
  • 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。
6 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
参考例句:
  • 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》
7 astronomers 569155f16962e086bd7de77deceefcbd     
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》
8 observatory hRgzP     
n.天文台,气象台,瞭望台,观测台
参考例句:
  • 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。
9 infrared dx0yp     
adj./n.红外线(的)
参考例句:
  • Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
  • Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。
10 astronomical keTyO     
adj.天文学的,(数字)极大的
参考例句:
  • He was an expert on ancient Chinese astronomical literature.他是研究中国古代天文学文献的专家。
  • Houses in the village are selling for astronomical prices.乡村的房价正在飙升。
11 friction JQMzr     
n.摩擦,摩擦力
参考例句:
  • When Joan returned to work,the friction between them increased.琼回来工作后,他们之间的摩擦加剧了。
  • Friction acts on moving bodies and brings them to a stop.摩擦力作用于运动着的物体,并使其停止。
12 remains 1kMzTy     
n.剩余物,残留物;遗体,遗迹
参考例句:
  • He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
  • The remains of the meal were fed to the dog.残羹剩饭喂狗了。
13 doomed EuuzC1     
命定的
参考例句:
  • The court doomed the accused to a long term of imprisonment. 法庭判处被告长期监禁。
  • A country ruled by an iron hand is doomed to suffer. 被铁腕人物统治的国家定会遭受不幸的。
TAG标签: planet black asteroids
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