太陽單調(diào)的性格可能是個好消息

The sun appears to be far less active than similar stars in terms of brightness variations caused by sunspots and other phenomena – a “boring” personality, according to scientists, that may not be a bad thing for us Earthlings.

就太陽黑子和其他現(xiàn)象引起的亮度變化而言，太陽似乎遠不如類似恒星活躍——科學(xué)家認為，這種“無聊”的性格對我們地球人來說可能不是壞事。

Researchers said on Thursday that an examination of 369 stars similar to the sun in surface temperatures, size and rotation period – it takes the sun about 24-1/2 days to rotate once on its axis – showed that they displayed on average five times more brightness variability than the sun.

研究人員周四表示，對369顆與太陽相似的恒星在表面溫度、大小和自轉(zhuǎn)周期(太陽繞其軸旋轉(zhuǎn)一次大約需要24-1/2天)的檢查顯示，它們的亮度變化平均是太陽的5倍。

“This variability is caused by dark spots on the surface of the star rotating in and out of view,” said astronomer Timo Reinhold of the Max Planck Institute for Solar System Research in Germany, lead author of the research published in the journal Science. “A direct measure of solar activity is the number of sunspots on the surface.”

德國馬克斯普朗克太陽系研究所的天文學(xué)家蒂莫·雷因霍爾德說：“這種變化是由于恒星表面的黑點在視圖內(nèi)外旋轉(zhuǎn)造成的。”他是發(fā)表在《科學(xué)》雜志上的這項研究的主要作者。“太陽活動的一個直接衡量標準是表面太陽黑子的數(shù)量。”

The sun – essentially a hot ball of hydrogen and helium – is an average-sized star that formed more than 4.5 billion years ago and is roughly halfway through its lifespan. Its diameter is about 864,000 miles. Its surface temperature is about 10,000 degrees Fahrenheit.

太陽-本質(zhì)上是氫和氦的熱球-是一顆平均大小的恒星，形成于45億年前，大約是其壽命的一半。它的直徑約為864,000英里。其表面溫度約為10,000華氏度。

“Temperature and rotation period are thought to be the major ingredients for the dynamo inside the star, which generates its magnetic field and eventually the number and size of the spots causing the brightness to vary. Finding such stars with very similar parameters as our sun but being five times more variable was surprising,” Reinhold said.

“溫度和旋轉(zhuǎn)周期被認為是恒星內(nèi)部發(fā)電機的主要組成部分，發(fā)電機產(chǎn)生磁場，并最終產(chǎn)生導(dǎo)致亮度變化的斑點數(shù)量和大小。”雷因霍爾德說：“發(fā)現(xiàn)這樣的恒星，其參數(shù)與我們的太陽非常相似，但變數(shù)卻是太陽的五倍，這令人驚訝。”。

Elevated magnetic activity associated with sunspots can lead to solar flares, coronal mass ejections – large expulsions of plasma and magnetic field from the outermost part of the sun’s atmosphere – and other electromagnetic phenomena that can affect Earth, for example disrupting satellites and communications and endangering astronauts.

與太陽黑子相關(guān)的高磁活動可導(dǎo)致太陽耀斑、日冕物質(zhì)拋射(太陽大氣最外層的等離子體和磁場被大幅度排出)和其他可能影響地球的電磁現(xiàn)象，例如擾亂衛(wèi)星和通信，危及宇航員。

Solar monotony may be good news.

太陽單調(diào)的性格可能是個好消息。

“A much more active sun might have also affected Earth on geological time scales – paleoclimatology. A ‘too active’ star would definitively change the conditions for life on the planet, so living with a quite boring star is not the worst option,” Reinhold said.

“一個更活躍的太陽可能也在地質(zhì)時間尺度上影響了地球——古氣候?qū)W。”雷因霍爾德說：“一顆‘太活躍’的恒星將徹底改變地球上的生命狀況，因此，與一顆相當(dāng)無聊的恒星一起生活并不是最壞的選擇。”。

The researchers compared data on the similar stars to historical records of the sun’s activity. These records included about 400 years of observational data on sunspots and about 9,000 years of data based on chemical element variants in tree rings and ice cores caused by solar activity. These records indicated the sun has not been much more active than it is now.

研究人員將類似恒星的數(shù)據(jù)與太陽活動的歷史記錄進行了比較。這些記錄包括大約400年的太陽黑子觀測數(shù)據(jù)，和大約9000年的基于太陽活動引起的樹輪和冰芯中化學(xué)元素變化的數(shù)據(jù)。這些記錄表明太陽并沒有比現(xiàn)在活躍得多。

The findings, Reinhold said, do not rule out that the sun may be in a quiet phase and may become more variable in the future.

雷因霍爾德說，這些發(fā)現(xiàn)不排除太陽可能處于平靜階段，未來也有可能變得更加多變。