It was Galileo who first studied the dark spots found in the Sun which are now referred to as sunspots. It is believed that the intense magnetic fields surrounding the sun cause the appearance of sunspots.
a sunspot
A "sunspot."
Sunspot. See related question
i belive it is a sunspot
A cooler area on the sun is called a sunspot
Well, a sunspot is not really dark but it is at a lower temperature than the surrounding gases on the surface of the Sun. So it only looks dark by contrast with the area round it.
The dark area is known as a sunspot on the Sun's surface. Sunspots appear darker because they are cooler than their surroundings. They are caused by strong magnetic activity that inhibits convection and reduces temperature.
Umbra.
The darkest part, where the magnetic field is approximately vertical to the sun's surface is called the Umbra.
A cool, dark area on the sun's surface is called a sunspot. Sunspots are areas of reduced temperature that appear dark against the brighter background of the surrounding solar surface because they are regions of concentrated magnetic field flux inhibiting convective flow.
Sunspots are dark circles on the sun's surface that are cooler than the area surrounding it. Another name for a sunspot is a solar variation or a dark spot.
An area on the sun that is cooler is called a sunspot.