Fotosfären

Fotosfären, also known as photospheres, are the visible surfaces of stars, including our Sun. They are the layers where the star's energy is radiated outward into space. The term "photosphere" comes from the Greek words "photos," meaning light, and "sphaira," meaning sphere. The photosphere is the deepest layer of a star that we can observe directly. It is the layer where the star's surface temperature is around 5,500 degrees Celsius for the Sun, and it emits the visible light that we see.

The photosphere is not a solid surface but rather a layer of gas. It is the region where the star's energy is converted from thermal energy to electromagnetic radiation. The photosphere is also the layer where sunspots, which are temporary phenomena on the photosphere marked by intense magnetic activity, appear. These sunspots are cooler than the surrounding photosphere and appear darker.

The thickness of the photosphere varies depending on the star. For the Sun, it is about 500 kilometers thick. The photosphere is an important layer for studying stellar activity and understanding the processes that occur within stars. Observations of the photosphere can provide valuable information about a star's temperature, composition, and magnetic activity.