天文学家首次近距离观测柱一座暗伴星
文章来源:未知 文章作者:meng 发布时间:2010-04-08 01:34 字体: [ ]  进入论坛
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For the first time, astronomers1 have directly observed the mysterious dark companion in a binary2 star(双子星) system that has puzzled skywatchers since the 19th century. Using an instrument developed at the University of Michigan, scientists have taken close-up pictures of Epsilon Aurigae during its eclipse, which happens every 27 years. "Close up" in this case is a relative term, but the images zoom3 in enough to show the shape of the dark object's shadow.

"Seeing is believing," said John Monnier, an associate professor in the U-M Department of Astronomy who is an author of a paper about the research findings published in the April 8 edition of Nature. Researchers from the University of Denver and Georgia State University were involved as well.

Epsilon Aurigae is the fifth brightest star in the northern constellation4(星座,荟萃) Auriga. For more than 175 years, astronomers have known it is dimmer than it should be, given its mass. They also noticed its brightness dip for more than a year every few decades. They surmised5(猜测,推测) that it was a binary system(二进制) in which one companion was invisible. But what type of object was the companion?

Because astronomers hadn't observed much light from it, the prevailing6(一般的,流行的) theory labeled it a smaller star orbited edge-on by a thick disk of dust. The theory held that the disk's orbit must be in precisely7 the same plane as the dark object's orbit around the brighter star, and all of this had to be occurring in the same plane as Earth's vantage point(有利位置,优势) . This would be an unlikely alignment8(结盟,队列) , but it explained observations.

The new images show that this is indeed the case. A geometrically thin, dark, dense9, but partially10 translucent11(透明的) cloud can be seen passing in front of Epsilon Aurigae.

"This really shows that the basic paradigm12(范例,词形变化表) was right, despite the slim probability," Monnier said. "It kind of blows my mind that we could capture this. There's no other system like this known. On top of that, it seems to be in a rare phase of stellar life. And it happens to be so close to us. It's extremely fortuitous(意外的,偶然的) ."

The disk appears much flatter than recent modeling from the Spitzer Space Telescope suggests, Monnier said.

"It's really flat as a pancake," he said.

Monnier led the creation of the Michigan Infra-Red Combiner (MIRC) instrument that was used to produce these images. MIRC uses a process called "interferometry(干扰量度法) " to combine the light entering four telescopes at the CHARA array at Georgia State University and amplify13 it so that it seems to be coming through a device 100 times larger than the Hubble Space Telescope.

MIRC allowed astronomers to see the shape and surface characteristics of stars for the first time. Previously14, stars were mere15 points of light even with the largest telescopes.

"Interferometry has made high resolution imaging of distant objects a reality," said Fabien Baron16, a post-doctoral researcher in the Department of Astronomy who helped with the imaging in this study. "It most probably will solve many mysteries but also raise many new questions."



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1 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》
2 binary jybzWZ     
adj.二,双;二进制的;n.双(体);联星
参考例句:
  • Computers operate using binary numbers.计算机运行运用二进位制。
  • Let us try converting the number itself to binary.我们试一试,把这个数本身变成二进制数。
3 zoom VenzWT     
n.急速上升;v.突然扩大,急速上升
参考例句:
  • The airplane's zoom carried it above the clouds.飞机的陡直上升使它飞到云层之上。
  • I live near an airport and the zoom of passing planes can be heard night and day.我住在一个飞机场附近,昼夜都能听到飞机飞过的嗡嗡声。
4 constellation CptzI     
n.星座n.灿烂的一群
参考例句:
  • A constellation is a pattern of stars as seen from the earth. 一个星座只是从地球上看到的某些恒星的一种样子。
  • The Big Dipper is not by itself a constellation. 北斗七星本身不是一个星座。
5 surmised b42dd4710fe89732a842341fc04537f6     
v.臆测,推断( surmise的过去式和过去分词 );揣测;猜想
参考例句:
  • From the looks on their faces, I surmised that they had had an argument. 看他们的脸色,我猜想他们之间发生了争执。
  • From his letter I surmised that he was unhappy. 我从他的信中推测他并不快乐。 来自《简明英汉词典》
6 prevailing E1ozF     
adj.盛行的;占优势的;主要的
参考例句:
  • She wears a fashionable hair style prevailing in the city.她的发型是这个城市流行的款式。
  • This reflects attitudes and values prevailing in society.这反映了社会上盛行的态度和价值观。
7 precisely zlWzUb     
adv.恰好,正好,精确地,细致地
参考例句:
  • It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
  • The man adjusted very precisely.那个人调得很准。
8 alignment LK8yZ     
n.队列;结盟,联合
参考例句:
  • The church should have no political alignment.教会不应与政治结盟。
  • Britain formed a close alignment with Egypt in the last century.英国在上个世纪与埃及结成了紧密的联盟。
9 dense aONzX     
a.密集的,稠密的,浓密的;密度大的
参考例句:
  • 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。
10 partially yL7xm     
adv.部分地,从某些方面讲
参考例句:
  • The door was partially concealed by the drapes.门有一部分被门帘遮住了。
  • The police managed to restore calm and the curfew was partially lifted.警方设法恢复了平静,宵禁部分解除。
11 translucent yniwY     
adj.半透明的;透明的
参考例句:
  • The building is roofed entirely with translucent corrugated plastic.这座建筑完全用半透明瓦楞塑料封顶。
  • A small difference between them will render the composite translucent.微小的差别,也会使复合材料变成半透明。
12 paradigm c48zJ     
n.例子,模范,词形变化表
参考例句:
  • He had become the paradigm of the successful man. 他已经成为成功人士的典范。
  • Moreover,the results of this research can be the new learning paradigm for digital design studios.除此之外,本研究的研究成果也可以为数位设计课程建立一个新的学习范例。
13 amplify iwGzw     
vt.放大,增强;详述,详加解说
参考例句:
  • The new manager wants to amplify the company.新经理想要扩大公司。
  • Please amplify your remarks by giving us some examples.请举例详述你的话。
14 previously bkzzzC     
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。
15 mere rC1xE     
adj.纯粹的;仅仅,只不过
参考例句:
  • That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
  • It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。
16 baron XdSyp     
n.男爵;(商业界等)巨头,大王
参考例句:
  • Henry Ford was an automobile baron.亨利·福特是一位汽车业巨头。
  • The baron lived in a strong castle.男爵住在一座坚固的城堡中。
TAG标签: dark light star system
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