銀河系的質(zhì)量相當于8900億個太陽

銀河系的質(zhì)量相當于8900億個太陽

The Milky Way has a mass that’s 890 billion times the mass of our sun.

銀河系的質(zhì)量是太陽的8900億倍。

That figure, as Live Science reports, is 3.9 tredecillion pounds — or the number 1 followed by 42 zeros. The mass is also equal to about 6 billion billion billion elephants, the science outlet reports.

據(jù)《生活科學》報道，這個數(shù)字是3.9萬億磅，也就是1后面跟42個0。據(jù)《科學出口》報道，大象的重量也相當于60億億億頭大象。

It’s challenging to measure the mass of a galaxy that we occupy, however.

然而，測量我們所在星系的質(zhì)量是一項挑戰(zhàn)。

Researchers tend to “weigh” them by examining the movements of stars inside the galaxies, which can demonstrate how the galaxy’s gravity is impacting those stars.

研究人員傾向于通過觀察星系內(nèi)恒星的運動來“衡量”它們，這可以證明星系的引力是如何影響這些恒星的。

“The disk of our galaxy is spinning but not uniformly,” study co-author Fabio Iocco, an astrophysicist at Imperial College London, told Live Science. “Objects at different distances from the center of the galaxy go around that center at different speeds.”

倫敦帝國理工學院的天體物理學家Fabio Iocco是這項研究的共同作者，他告訴Live Science:“我們星系的圓盤在旋轉(zhuǎn)，但是并不均勻。”“距離星系中心不同距離的物體以不同的速度圍繞該中心旋轉(zhuǎn)。”

The researchers reportedly compared their findings with previous work in this area and found that they lined up. Their paper was made available Monday in the arXiv database.

據(jù)報道，研究人員將他們的發(fā)現(xiàn)與之前在這一領(lǐng)域的研究結(jié)果進行了比較，發(fā)現(xiàn)結(jié)果是一致的。他們的論文于周一發(fā)布在arXiv數(shù)據(jù)庫中。

“If you do it for different distances, from the center until very far away, you get an estimate of the mass enclosed at increasing distances. So you can draw not only a total mass, but a mass distribution,” Iocco told Live Science.

“如果你從中心到很遠的地方，從不同的距離計算，你會得到距離增加時的質(zhì)量估計值。所以你不僅可以畫出總質(zhì)量，還可以畫出質(zhì)量分布。”