Sunspots come and go. Occasionally, sunspots on the Sun are large enough to be visible to the naked eye. Everyday, we observe and keep record of the sunspot activities. The purpose of the observation is to collect data of sunspot activity for future research. Sunspot are regions of the photosphere where the gases are up to 1500K cooler than those of the surrounding photosphere.
Sunspots are nevertheless hotter than the surfaces of many stars.
If they could be removed from the Sun , they would be seen to shine brightly. They appear dark only by contrast with the hotter, brighter surrounding photosphere. Individual unspot have lifetimes that range from a few hours to a few months. Many spots become much larger than the Earth , and a few have reached diameters of 50,000km. Frequently spots occur in groups of 2 to 20 or more.