by James Weightman
Sunspots are dark regions on the surface of the Sun that appear darker than the surrounding area. They are caused by strong magnetic fields that emerge through the photosphere, or surface, of the Sun.
Sunspots consist of two main regions:
the Umbra: a central dark region, which is cooler (about 3500°C) compared to the surrounding photosphere (about 5,500°C),
and the Penumbra: the surrounding region that is also cooler and lighter.
On average, sunspots are about the same size as Earth, although they can vary significantly in size from hundreds to tens of thousands of miles across; a group of sunspots as seen in these photos is known as an ‘active region’.
The frequency and intensity of sunspots visible on the Sun’s surface indicate the level of solar activity during the 11-year solar cycle which is driven by the Sun’s magnetic field. Sunspots play a significant role in generating solar flares and coronal mass ejections (CMEs), which can impact space weather and Earth’s environment.