• Stellar Evolutionary Tracks
• Nucleosynthesis Processes
• Astronomy Quiz

Java Astro Lab: A Collection of Applets for Astronomy

Nucleosynthesis Processes

Stars like our Sun generate energy by fusing Hydrogen into Helium. Several chain reactions 4 (¹₁H) -> ⁴₂He are possible, depending on temperature in the center of the star. When this temperature is below 20 million K, the reactions take the proton - proton (PP) chain path:

The first reaction in the PP chain:

¹₁H + ¹₁H -> ²₁H + e⁺+_e

(Java animation).


The second reaction in the PP chain:

²₁H+ ¹₁H -> ³₂He +

(Java animation)


The third reaction in the PP chain:

  ³₂He + ³₂He-> ⁴₂He + 2( ¹₁H)

(Java animation)


Credits: The JAVA animations were made using the Collision applet created by Nicolas Delerue.