It is five times hotter than the photosphere. Above the chromosphere is an area called the corona, which is made up of two parts. The inner corona changes its shape sometimes looking like a fan or a flame. This is the part of the sun that is visible during an eclipse. The outer corona is invisible and is made up of very thin gasses.
Sunspots are cool areas on the sun s surface.
They do not put out as much light as the hotter areas, so they appear to be dark spots when viewed from Earth. Sunspots can be small, around 600 miles wide, or as large as thousands of miles across. The number of visible sunspots varies between five and 100. Most sunspots are made up of two parts. The smaller inner part is called the umbra , the darkest area.