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[转帖文章] 星星的数量可能将增加到我们现在已知的3倍

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shinobii 发表于 2010-12-2 15:01 | 显示全部楼层 |阅读模式 来自: 加拿大 里贾纳大学

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太懒了,我就不翻译了 Discovery May Triple the Number of Stars In the Universe

来源: http://beta.ca.news.yahoo.com/discovery-may-triple-number-stars-universe.html




Stars known as red dwarfs might be far more common than previously thought, enough to triple the total number of stars known in the universe, a new study suggests.
These new findings could also boost the number of planets that could harbor life, astronomers announced today (Dec. 1).
Red dwarfs are dim compared to stars such as our sun and just 10 to 20 percent as massive. As such, astronomers could not detect them in galaxies other than our Milky Way and its closest neighbors until now.
Now astronomers have used powerful scientific instruments on the W.M. Keck Observatory in Hawaii to detect the faint signature of red dwarfs in eight massive so-called elliptical galaxies located between about 50 million and 300 million light-years away.
"It is remarkable that we can measure and quantify the light of these incredibly feeble stars in galaxies outside of the Milky Way," researcher Pieter van Dokkum, an astronomer at Yale University, told SPACE.com.
Elliptical galaxies are some of the largest galaxies in the universe. The largest of these galaxies were thought to hold more than 1 trillion stars (compared with the 400 billion stars in our Milky Way). [Top 10 Star Mysteries]
The new finding suggests there may be five to 10 times as many stars inside elliptical galaxies than previously thought, which would triple the total number of known stars in the universe, researchers said.
The final, total tally for the number of stars in the universe still remains murky, the scientists cautioned. Determining the total star population of the cosmos requires an accurate number for galaxies as well, they added.
"It's this latter quantity that is quite uncertain. Nevertheless, best estimates are around 100 sextillion – a 1 with 23 zeros," van Dokkum said. "Our results would then triple that number, but again, there's a large additional uncertainty associated with this estimate."
The researchers' computer models based on these findings suggest that red dwarfs are far more common than expected, with these galaxies each possessing roughly 20 times more red dwarfs on average than the Milky Way, said researcher Charlie Conroy, an astronomer at the Harvard-Smithsonian Center for Astrophysics.
"The abundance of these stars is very surprising — there are many more than we had expected," van Dokkum said.
All in all, red dwarfs could make up at least 80 percent of the total number of stars and at least 60 percent of all the mass found in stars.
"No one knew how many of these stars there were," van Dokkum said. "Different theoretical models predicted a wide range of possibilities, so this answers a longstanding question about just how abundant these stars are."
These findings suggest that galaxies might contain less of the mysterious substance labeled "dark matter" than before thought. Instead, red dwarfs could contribute more mass than realized.
"We need to revise current estimates of the masses and star formation activity of nearby and distant galaxies," van Dokkum said.
Moreover, the increased number of red dwarfs means there could increase the number of planets orbiting stars, which in turn boosts the number of potentially habitable planets.
To date, astronomers have discovered just over 500 alien planets around other stars.
"There are possibly trillions of Earths orbiting these stars," van Dokkum said. He added that the red dwarfs they discovered, which are typically more than 10 billion years old, have been around long enough for complex life to evolve. "It's one reason why people are interested in this type of star."
Van Dokkum and Conroy detail their findings in the Dec. 2 issue of the journal Nature.
errai 发表于 2010-12-2 15:28 | 显示全部楼层 来自: 中国–浙江–宁波 电信
不止3倍吧.....我们知道的有几颗啊..............................
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索理客 发表于 2010-12-2 17:56 | 显示全部楼层 来自: 中国–江苏–南京 电信
本帖最后由 sonic5188 于 2010-12-2 18:14 编辑

当然了,以前都是只算到红矮星的,比太阳小的矮星占宇宙红矮星以上恒星数量的93%,现在褐矮星数量会更多
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inter06 发表于 2010-12-2 17:59 | 显示全部楼层 来自: 中国–北京–北京 鹏博士BGP
本帖最后由 inter06 于 2010-12-2 18:00 编辑

也就是说,银河系里应该是6000亿颗恒星?
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davidhan5566 发表于 2010-12-2 23:26 | 显示全部楼层 来自: 中国–浙江–宁波 电信
就当测试自己现在的英文水平吧~~~看看裸看究竟能看懂多少~~~
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gohomeman1 发表于 2010-12-3 00:22 | 显示全部楼层 来自: 中国–浙江–宁波 联通/鄞州畅联信息技术有限公司
大概的内容,参考另一个帖子吧:
http://www.astronomy.com.cn/bbs/thread-153426-1-1.html
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