What are stellar atmospheres composed of?
1 Answer
Stellar atmospheres are mainly hydrogen.
Explanation:
Stars are mainly hydrogen and some helium. Stars can have small amounts of heavier elements in their atmosphere. The actual composition depends on the composition of the nebula from which the star formed.
A star's core is where fusion reactions take place to make heavier elements. The Sun's core extends to between 20% and 25% of its radius. Convection currents can allow fusion products to leave the core and enter the atmosphere.
Larger stars produce heavier elements up to iron. The star is effectively layered. The outer layer is still mainly hydrogen. Progressively heavier elements form layers.
When large stars reach the end of their life their core can collapse and trigger rapid fusion in the layers around the core which cause the star to explode as a supernova. The outer layers are still mainly hydrogen. The explosion spreads the star's atmosphere out to form a nebula. The nebula will have enough hydrogen for another star to form from it.
