科学60秒:繁星满天
来源：沪江听写酷
2011-06-20 10:00
只听些5个空即可。
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.
【视听版科学小组荣誉出品】
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.
【视听版科学小组荣誉出品】
faint
elliptical
light-years
theorized
ubiquitous
繁星满天
在许多凝望星空的人眼里，星星多得简直数不胜数。当然，天文学家可不会这么认为，但是他们最近发现宇宙的恒星可能比想象中要多上许多。
红矮星只有我们太阳大小的1/10到1/20。由于它们的光芒太过微弱，天文学家发现不了河外星系以及邻近星系的红矮星。
因此研究人员在夏威夷凯克天文台用一些灵敏的仪器来寻找红矮星。他们在8个的大型椭圆星系中发现了红矮星发出的微弱信号，这些星系离我们相对较近——它们的距离都在5千万到3亿光年之间。而且研究人员发现，这些星系的红矮星数量比银河多20倍。
这个发现让天文学家相信宇宙的恒星可能比先前理论推测的要多3倍。这项研究发表在《自然》杂志上。
而近期一项研究发现了在红矮星周围绕轨道运行的系外行星有着和地球相似的特征。研究带头人派特·范·多克姆表示，在遍布宇宙的红矮星周围，可能有上万亿个地球一样的行星在绕着轨道运行。