Q&A: General Astronomy and Space Science

Q:
Could you explain what nucleosynthesis is?

A:
We have a brief description of nucleosynthesis in our glossary: http://chandra.harvard.edu/resources/glossaryN.html, but after you read the definition, "the building up of heavy elements from lighter ones by nuclear fusion," you might want an example of this phenomenon. Our Sun is a good example of a nucleosynthesis machine. It takes 2 hydrogen nuclei, which are just single protons which sometimes come with a neutron or two, and fuses them together in the hot oven that is the Sun's deepest interior, into helium nuclei.

The nice part of the process of stellar nucleosynthesis is that the final nuclei is lighter than the sum of the hydrogen nuclei, so that the process gives off energy. That's why the Sun shines and why we're here today.

There is a definition of nuclear fusion directly above the entry for nucleosynthesis. Nuclear fusion is exactly what it sounds like, the fusing together of nuclei to form bigger nuclei.