ASTR 110G Chapter Notes - Chapter 15.3: Rubber Band, Corona, Solar Flare
Document Summary
Sunspots are not the only features that vary during a solar cycle. There are dramatic changes in the chromosphere and corona as well. As we saw, emission line of hydrogen and calcium are produced in the hot gases of the chromosphere. Astronomers routinely photograph the sun through filters that transmit light only at the wavelengths that correspond to these emission lines. Pictures taken through these special filters show bright "clouds" in the chromosphere around sunspots; these bright regions are known as plages. The plages actually contain all of the elements in the sun, not just hydrogen and calcium. Moving higher into the sun"s atmosphere, we come to the spectacular phenomena called prominences, which usually originate near sunspots. Eclipse observers often see prominences as red features rising above the eclipsed sun and reaching high into the corona. Some, the quiescent prominences, are graceful loops of plasms that can remain nearly stable for many hours or even days.
