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.
Sunspots.
They are transitory.
solar flares appear as a dark spot
The darkest part, where the magnetic field is approximately vertical to the sun's surface is called the Umbra.
No. That spot is light and it is day.
there is about over 10,000,000 sun spots on the sun
A "sunspot."
Sunspots. They are only "cool" relative to the rest of the Sun.
Yes I have seen a dark spot on the Sun. It is called a "Sunspot". It is formed on the Sun's surface which is called the "photo-sphere" and is caused by a loop of the Sun's magnetic field poking though the Sun's surface.
Dark spots that appear on the surface of the sun are called sunspots. They are areas of reduced temperature caused by interactions with the sun's magnetic field.
Sunspots
He looked at the sun and observed dark blemishes on its surface, which are now called sunspots. From the movement of these, he was able to determine that the sun has a rotation period of about one month.