Neon-burning process

This article has multiple issues. Please help or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help by introducing citations to additional sources. Find sources:  –  ·  ·  · scholar · JSTOR (March 2014) This article needs additional citations for verification. Please help by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources:  –  ·  ·  · scholar · JSTOR (March 2014) (Learn how and when to remove this template message) (Learn how and when to remove this template message)

The neon-burning process (nuclear decay) is a set of nuclear fusion reactions that take place in evolved massive stars with at least 8 Solar masses. Neon burning requires high temperatures and densities (around 1.2×10⁹ K or 100 keV and 4×10⁹ kg/m³).

At such high temperatures photodisintegration becomes a significant effect, so some neon nuclei decompose, releasing alpha particles:^[1]

20 10Ne	+	γ	→	16 8O	+	4 2He
20 10Ne	+	4 2He	→	24 12Mg	+	γ

Alternatively:

20 10Ne	+	n	→	21 10Ne	+	γ
21 10Ne	+	4 2He	→	24 12Mg	+	n

where the neutron consumed in the first step is regenerated in the second.

Neon burning takes place after carbon burning has consumed all carbon in the core and built up a new oxygen–neon–sodium–magnesium core. The core ceases producing fusion energy and contracts. This contraction increases density and temperature up to the ignition point of neon burning. The increased temperature around the core allows carbon to burn in a shell, and there will be shells burning helium and hydrogen outside.

During neon burning, oxygen and magnesium accumulate in the central core while neon is consumed. After a few years the star consumes all its neon and the core ceases producing fusion energy and contracts. Again, gravitational pressure takes over and compresses the central core, increasing its density and temperature until the oxygen-burning process can start.

See also[]

• Carbon-burning process
• Oxygen-burning process

References[]

External links[]

• Arnett, W. D. Advanced evolution of massive stars. V – Neon burning / Astrophysical Journal, vol. 193, Oct. 1, 1974, pt. 1, p. 169–176.

This star-related article is a stub. You can help Wikipedia by .

• v
• t