Main Sequence
Basic Parts of a Star
Inner Parts
1. Core
Starting at the center of a star is the Core. It is the part of the star that is deep within the center where nuclear fusion takes place and the only part of a star where fusion takes place. The Core has enormous amounts of pressure which causes nuclear fusion.
2. Radiation Zone
The Radiation Zone, the middle section of the inner area, where the energy from the Core is transmitted into electromagnetic radiation. The Radiation Zone is very dense and makes energy waves bounce around. Because it is so dense it is very hard for energy to be released from this zone, it may take millions of years for the energy to leave the Radiation Zone.
3. Convection Zone
The Convection Zone is the last part of the inner portion of a star. The stellar convection consists of plasma within the star usually forms a circular motioned current. The hotter plasma moves toward the top of the convection zone and the cooler plasma moves toward the bottom of the zone where it then becomes heated. In this zone, energy moves through convection hence the name, Convection Zone.
Starting at the center of a star is the Core. It is the part of the star that is deep within the center where nuclear fusion takes place and the only part of a star where fusion takes place. The Core has enormous amounts of pressure which causes nuclear fusion.
2. Radiation Zone
The Radiation Zone, the middle section of the inner area, where the energy from the Core is transmitted into electromagnetic radiation. The Radiation Zone is very dense and makes energy waves bounce around. Because it is so dense it is very hard for energy to be released from this zone, it may take millions of years for the energy to leave the Radiation Zone.
3. Convection Zone
The Convection Zone is the last part of the inner portion of a star. The stellar convection consists of plasma within the star usually forms a circular motioned current. The hotter plasma moves toward the top of the convection zone and the cooler plasma moves toward the bottom of the zone where it then becomes heated. In this zone, energy moves through convection hence the name, Convection Zone.
Outer Parts
4. Photosphere
The Photosphere is the visible outer layer of a star. It is the thickest and largest part of a star, taking up almost 2/3's of the entire star. The Photosphere is so thick that it appears to be a solid surface.
5. Corona
The Corona is the outermost layer of a stars atmosphere. The Corona is made of hot plasma and is almost like a star's atmosphere.
The Photosphere is the visible outer layer of a star. It is the thickest and largest part of a star, taking up almost 2/3's of the entire star. The Photosphere is so thick that it appears to be a solid surface.
5. Corona
The Corona is the outermost layer of a stars atmosphere. The Corona is made of hot plasma and is almost like a star's atmosphere.
To learn more about the parts of a star click the following links:
Core Radiation Zone Convection Zone Photosphere Corona |
Expansion and Contraction
Main sequence stars, like Fomalhaut do not expand or contract because the gravity of the star that is pulling the materials towards the center. While the gravity pulls inward, nuclear fusion is creating an outward push as it creates helium and heavier elements. The gravity pulls inward while fusion pushes outward and that balances out the star so it is not expanding or contracting.
Composition of Physical Fomalhaut
H-R Diagram
Fomalhaut on the H-R Diagram
Here is a H-R Diagram with Fomalhaut plotted on it. You can see in this diagram that Fomalhaut is not the biggest or the smallest star, it is somewhere in the middle. Fomalhaut isn’t the hottest or coolest star either, it is also in near the middle as a Class A star. Fomalhaut is a white main sequence star, it is white even though it looks red in pictures. It has a stellar classification of A3V which helps classify Fomalhaut on the H-R Diagram and also tells you its brightness and temperature. Stars spend most of their lives on the Main Sequence but when hydrogen and other elements start to decrease it enters the death stages. |