太阳单调的性格可能是个好消息

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.

就太阳黑子和其他现象引起的亮度变化而言，太阳似乎远不如类似恒星活跃——科学家认为，这种“无聊”的性格对我们地球人来说可能不是坏事。

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.

研究人员周四表示，对369颗与太阳相似的恒星在表面温度、大小和自转周期(太阳绕其轴旋转一次大约需要24-1/2天)的检查显示，它们的亮度变化平均是太阳的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.”

德国马克斯普朗克太阳系研究所的天文学家蒂莫·雷因霍尔德说：“这种变化是由于恒星表面的黑点在视图内外旋转造成的。”他是发表在《科学》杂志上的这项研究的主要作者。“太阳活动的一个直接衡量标准是表面太阳黑子的数量。”

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.

太阳-本质上是氢和氦的热球-是一颗平均大小的恒星，形成于45亿年前，大约是其寿命的一半。它的直径约为864,000英里。其表面温度约为10,000华氏度。

“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.

“温度和旋转周期被认为是恒星内部发电机的主要组成部分，发电机产生磁场，并最终产生导致亮度变化的斑点数量和大小。”雷因霍尔德说：“发现这样的恒星，其参数与我们的太阳非常相似，但变数却是太阳的五倍，这令人惊讶。”。

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.

与太阳黑子相关的高磁活动可导致太阳耀斑、日冕物质抛射(太阳大气最外层的等离子体和磁场被大幅度排出)和其他可能影响地球的电磁现象，例如扰乱卫星和通信，危及宇航员。

Solar monotony may be good news.

太阳单调的性格可能是个好消息。

“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.

“一个更活跃的太阳可能也在地质时间尺度上影响了地球——古气候学。”雷因霍尔德说：“一颗‘太活跃’的恒星将彻底改变地球上的生命状况，因此，与一颗相当无聊的恒星一起生活并不是最坏的选择。”。

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.

研究人员将类似恒星的数据与太阳活动的历史记录进行了比较。这些记录包括大约400年的太阳黑子观测数据，和大约9000年的基于太阳活动引起的树轮和冰芯中化学元素变化的数据。这些记录表明太阳并没有比现在活跃得多。

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.

雷因霍尔德说，这些发现不排除太阳可能处于平静阶段，未来也有可能变得更加多变。