2026年2月11日
A Year of Sunspots
Image Credit: NASA, SDO; Processing & Copyright: Şenol Şanli & Uğur İkizler; Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
Explanation: How many sunspots can you see? The central image shows the many sunspots that occurred in 2025, month by month around the circle, and all together in the grand central image. Each sunspot is magnetically cooled and so appears dark — and can last from days to months. Although the featured images originated from NASA‘s Solar Dynamics Observatory, sunspots can be easily seen with a small telescope or binoculars equipped with a solar filter. Very large sunspot groups like recent AR 4366 can even be seen with eclipse glasses. Sunspots are still counted by eye, but the total number is not considered exact because they frequently change and break up. Last year, 2025, coincided with a solar maximum, the period of most intense magnetic activity during its 11-year solar cycle. Our Sun remains unpredictable in many ways, including when it ejects solar flares that will impact the Earth, and how active the next solar cycle will be.
Tomorrow’s picture: open space
太阳黑子一流年
影像提供: NASA, SDO; 影像处理与版权: Şenol Şanli & Uğur İkizler; 文稿: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
说明: 你能在太阳表面看到多少颗太阳黑子呢？精选影像展示了2025年一整年中太阳黑子的月变化的分布：环状排列的影像显示每个月的黑子活动，并在中央叠加成一幅壮观全景。太阳黑子是因为太阳强磁场抑制对流、导致局部温度较低而形成，因此在视觉上以深色斑点呈现。单一黑子的生命期可短至数天，也可能长达数个月。虽然这些精选影像来自NASA的太阳动力学天文台（Solar Dynamics Observatory, SDO），但其实只要使用小型望远镜或双筒望远镜，并配备太阳滤镜，就能安全地观测到太阳黑子。在适当条件下，甚至戴着日食眼镜就能直接看见近期出现的超大型黑子群AR 4366。太阳黑子的数量至今仍主要靠「人工目视」来统计。不过，由于黑子会快速演化、分裂或消散，这个数字并不是完全精确。2025年正好落在太阳活动极大期（solar maximum），也就是太阳约11年活动周期中磁场最活跃的阶段。即便如此，太阳仍在许多方面难以预测，包括它何时会喷发影响地球的太阳闪焰，或是下一个太阳周期的活跃程度究竟如何。
明日的图片: open space
