The magnetic activity of stars like sun, which is the root cause of the sunspot cycle, is still poorly understood even after decades of intense study.

磁场的变化是像太阳这样的恒星表面黑子活动周期的根源，尽管经过几十年的认真研究之后，地球人仍然对其知之甚少。

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Sunspot activity, which follows an 11-year cycle, is due to peak in 2013 after which it will start to wane slightly.

虽然以11年为周期的太阳黑子活动将在2013年达到顶峰之后，将缓慢衰落。

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Before cycle 24 commenced, the position and strength of the torsional oscillation correctly predicted the late arrival of this cycle's sunspot activity.

在第24个周期开始前，人们通过太阳的扭转振动的位置和强度准确的预知了第24周期内太阳黑子活动的推迟。

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But in the current cycle, sunspot activity has collapsed.

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Sunspot activity waxes and wanes on the sun in a 11-year cycle, and we are approaching the peak of sunspot activity, probably reaching it in 2013, according to Hesse.

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