Properties of solar activity in the Dalton minimum

准确了解太阳活动周期的可变性对于理解太阳大范围磁场的产生是至关重要的。除了在17世纪下半叶研究得很好的蒙德极小值，几十年来太阳黑子很少，1800年左右的道尔顿极小值没有得到很好的研究。根据哥本哈根天文台最初的太阳黑子测量和HonoréFlaugergues的凌日观测，该提议旨在获得大量新的太阳黑子位置和面积、太阳黑子群倾角和道尔顿极小值附近的时间段的极性分离。这些位置还将使我们能够在道尔顿极小值之前确定太阳的差异自转。这段时期与目前的低周期第24周和未来太阳活动的发展进行了比较，这是很有趣的。

The precise knowledge of the variability of the solar activity cycle is essential for the understanding of the generation of large-scale magnetic fields in the Sun. Apart from the well studied Maunder minimum in the second half of the 17th century with very few sunspots for several decades, the Dalton minimum around 1800 is not investigated well. With the original sunspot measurements of Copenhagen Observatory and the transit observations by Honoré Flaugergues, the proposal aims to obtain a large number of new sunspot positions and areas, sunspot group tilt angles and polarity separations for the time around the Dalton minimum. The positions will also allow us to determine the differential rotation of the Sun just before the Dalton minimum. The period is interesting for a comparison with the present low cycle 24 and the future development of solar activity.