Labels:text | screenshot | font | number OCR: FACT FILE THE CENTRAL PART of a sunspot, the umbra, has a temperature of about 4,200 ℃ (7,600 ºF), which is about 1,500 ℃ (2,700 "F) cooler than the surrounding solar photosphere. Although the spots are glowing with heat, they appear dark against their hotter, brighter surroundings.
