PICK OF THE WEEK
Pick of The Week
Sunspots and active regions compared (September 4, 2001)
The Sun had in early September 2001 developed a good number of sunspots. These are somewhat cooler than the rest of the Sun's surface so they appear darker in the visible light image (right). Sunspots are also the visible traces of magnetically active regions seen in the ultraviolet image by EIT 304Å (left) taken at about the same time. |