Fotosfääriga

Fotosfääriga is a term that refers to the visible surface of a star, most commonly used in the context of our Sun. It is the layer from which most of the Sun's light is emitted, making it what we perceive as the Sun's bright disk. The fotosfääriga is a relatively thin layer, only about 100 to 400 kilometers thick. Its temperature ranges from approximately 4,000 to 7,500 Kelvin.

The fotosfääriga is characterized by its granular appearance. This granulation is caused by convection currents rising from deeper within the Sun. Hot plasma rises to the surface, cools, and then sinks back down. These rising and falling cells of plasma create the granular pattern. Darker areas within the granules are cooler, while brighter areas are hotter.

Sunspots are also observed on the fotosfääriga. These are temporary phenomena that appear as darker patches on the Sun's surface. Sunspots are cooler than their surroundings because of intense magnetic activity that inhibits convection, preventing heat from reaching the surface. The number of sunspots fluctuates in an approximately 11-year cycle.

Observations of the fotosfääriga have provided astronomers with crucial information about the Sun's composition, temperature, and activity. Spectroscopic analysis of the light emitted from the fotosfääriga allows scientists to determine the elements present in the Sun and their abundance. Studying the variations in the fotosfääriga also helps in understanding solar cycles and their potential impact on Earth's climate.