What Is Carbon Burning?
It’s a safe bet that many people are not familiar with the term “carbon burning.” We understand that a lot of what makes up our world – wood, paper etc. – burn, either intentionally or unintentionally. But we might be confused by carbon burning because it is not one of the things we encounter up close, on a daily basis.
This process is also known by the phrase “carbon fusion.” The reason we don’t encounter it on a regular basis is that it is a nuclear-fusion activity that takes place in large stars. When these stars have used up other parts of their core they move the carbon-burning stage. (The sun that warms and lights the earth is a massive star. Because stars burn they are visible in the night sky.)
Encyclopedia entries show several equations or sets of figures to illustrate fusion reactions such as carbon burning. These won’t help the non-scientist understand what is happening in the world of stars and other celestial objects. One of the simpler explanations of reactions such as carbon burning shows that two nuclei composed primarily of carbon move together and exist is an “excited” state for a time.
As these nuclei work together, they decay (burn up) releasing energy. Scientists have discovered that, in rare cases, this activity results in energy being absorbed by the mass, as opposed to being sent out as heat and light. Research has allowed scientists to develop at least two other theories about these reactions, one of which involves electromagnetic activity. The last result of a reaction such as carbon burning is believed to be rare because energy is absorbed and three distinct products come from this type of reaction.
Studies of various stars in our galaxy show that a form of oxygen is produced by a particular type of carbon burning. In stars of a particular size and mass 
some of the oxygen is used up while the majority of it survives. This has been of particular interest to scientists because oxygen is so essential to supporting life, as we understand it. Detailed research results include the basic statement, “So the end result of carbon burning is a mixture mainly of oxygen, neon and magnesium.” (Wikipedia)
Nuclear reactions such as carbon burning take place only when there is an extreme level of temperature. In addition, the particles must be forced together with large amounts of pressure. This last factor is primarily responsible for forcing the two carbon nuclei together as mentioned earlier.
One of the more interesting facts that scientists have uncovered is that fusion reactions such as carbon burning only take place when a star is in the later period of its life. Research also indicates that a star approaches a sufficient state of pressure in the core when it began its life with a minimum of four “solar” masses. It is also believed that carbon burning only occurs after the star has used up much of its helium and much of its hydrogen.
Theories and research results from studying carbon burning may tell us a lot about the inner workings of our solar system and about its age.
Category: Science