科學60秒:繁星滿天
來源：滬江聽寫酷
2011-06-20 10:00
只聽些5個空即可。
To many who stare up at the heavens, the stars may seem simply uncountable. Of course that’s not the attitude of astronomers. But they’ve made a discovery that means there are probably a lot more stars in the universe than they thought.
Red dwarfs are stars that are only 10 to 20 percent as massive as our sun. They’re so ____1____ that astronomers weren’t able to detect them in any galaxies other than our own Milky Way, and neighboring ones.
So researchers used sensitive instruments at the Keck Observatory in Hawaii. They found ____1____ signatures of these red dwarf stars in eight massive ____2____ galaxies relatively close to us—between 50 million and 300 million ____3____ away. And they discovered that these galaxies were home to 20 times as many red dwarfs as there are in the Milky Way.
The finding leads astronomers to believe that there may be three times as many stars in the universe as they’d previously ____4____. The research was published in the journal Nature.
And a recently discovered exoplanet orbiting a red dwarf had some Earth-like qualities. Lead researcher Pieter van Dokkum says there could be trillions of Earths orbiting the ____5____ red dwarfs.
【視聽版科學小組榮譽出品】
To many who stare up at the heavens, the stars may seem simply uncountable. Of course that’s not the attitude of astronomers. But they’ve made a discovery that means there are probably a lot more stars in the universe than they thought.
Red dwarfs are stars that are only 10 to 20 percent as massive as our sun. They’re so ____1____ that astronomers weren’t able to detect them in any galaxies other than our own Milky Way, and neighboring ones.
So researchers used sensitive instruments at the Keck Observatory in Hawaii. They found ____1____ signatures of these red dwarf stars in eight massive ____2____ galaxies relatively close to us—between 50 million and 300 million ____3____ away. And they discovered that these galaxies were home to 20 times as many red dwarfs as there are in the Milky Way.
The finding leads astronomers to believe that there may be three times as many stars in the universe as they’d previously ____4____. The research was published in the journal Nature.
And a recently discovered exoplanet orbiting a red dwarf had some Earth-like qualities. Lead researcher Pieter van Dokkum says there could be trillions of Earths orbiting the ____5____ red dwarfs.
【視聽版科學小組榮譽出品】
faint
elliptical
light-years
theorized
ubiquitous
繁星滿天
在許多凝望星空的人眼里，星星多得簡直數(shù)不勝數(shù)。當然，天文學家可不會這么認為，但是他們最近發(fā)現(xiàn)宇宙的恒星可能比想象中要多上許多。
紅矮星只有我們太陽大小的1/10到1/20。由于它們的光芒太過微弱，天文學家發(fā)現(xiàn)不了河外星系以及鄰近星系的紅矮星。
因此研究人員在夏威夷凱克天文臺用一些靈敏的儀器來尋找紅矮星。他們在8個的大型橢圓星系中發(fā)現(xiàn)了紅矮星發(fā)出的微弱信號，這些星系離我們相對較近——它們的距離都在5千萬到3億光年之間。而且研究人員發(fā)現(xiàn)，這些星系的紅矮星數(shù)量比銀河多20倍。
這個發(fā)現(xiàn)讓天文學家相信宇宙的恒星可能比先前理論推測的要多3倍。這項研究發(fā)表在《自然》雜志上。
而近期一項研究發(fā)現(xiàn)了在紅矮星周圍繞軌道運行的系外行星有著和地球相似的特征。研究帶頭人派特·范·多克姆表示，在遍布宇宙的紅矮星周圍，可能有上萬億個地球一樣的行星在繞著軌道運行。
