SUNSPOT

Sunspots form in the outermost layer of the Sun, called the light sphere. It appears as dark spots because its temperature is lower compared to its surroundings. Concentration of the magnetic field in certain areas prevents the even distribution of heat. As a result, regions that we call Sunspots, which have a lower surface temperature than the surrounding light sphere, are formed. These often appear in pairs. Both are opposite magnetic poles of each other.[2] Sunspots are clearly visible as black spots even if they have a temperature of approximately 3,000-4,500 K (2,700-4,200 °C). Because the surrounding regions have a temperature of approximately 5,780 K (5,500 °C). As with blackbody radiation, the luminous intensity of spots is directly proportional to the fourth power of its temperature. If we could separate the sunspots from the sphere of light forming its surroundings, it would appear much brighter than the Moon.[3] These spots both contract and expand as they travel across the Sun's surface. If we think of spots as circles, they can be small, 16 kilometers[4] in diameter, or large, 160,000 kilometers[5] in diameter. The larger ones can be seen from Earth even without a telescope.[6] They can also have relative velocities of several hundred meters per second when they first appear in the light sphere. Sunspots indicate intense magnetic activity, as do coronal loops and magnetic coupling events. Most solar flares and coronal mass ejections occur in active magnetic fields around regions where sunspots are grouped. Similar phenomena have been observed indirectly in stars other than the Sun, by measuring the light and dark regions. These are called star spots.