Oxygen-burning process

The oxygen-burning process is a set of nuclear fusion reactions that take place in massive stars that have used up the lighter elements in their cores. Oxygen-burning is preceded by the neon-burning process and succeeded by the silicon-burning process. As the neon-burning process ends, the core of the star contracts and heats until it reaches the ignition temperature for oxygen burning. Oxygen burning reactions are similar to those of carbon burning; however, they must occur at higher temperatures and densities due to the larger Coulomb barrier of oxygen.

Reactions

Oxygen ignites in the temperature range of (1.5–2.6)×10⁹ K and in the density range of (2.6–6.7)×10¹² kg·m⁻³. The principal reactions are given below, where the branching ratios assume that the deuteron channel is open (at high temperatures):

|- style="height:2em;"

| || || ||→ || ||+ ||

| +

|16.539 MeV

|- style="height:2em;"

| || || ||→ || ||+ ||2 Alpha particle|

| −

|0.393 MeV

|}

Near 2×10⁹ K, the oxygen-burning reaction rate is approximately 2.8×10⁻¹²(T₉/2)³³,