The Chemistry of Stars


We are told chemistry can be found everywhere, in everything. Well, what about stars? How much chemistry can really be found in stars, right? Everyone has spent a night just looking up at the stars, but most people don’t understand what stars are, or how they are formed. It turns out that there is a ton of chemistry involved, from the creation of stars to the moment they are destroyed. What would the night skies be without stars, and all of their chemistry? Stars are used for navigation, and play a huge roll in the myths of old.

Composition of ...

    • Hydrogen (H2)
    • Helium (He)
    • Carbon (C)
    • Nitrogen (N2)
    • Oxygen (O2)

Main Chemicals, Compounds, Components

Stars are about ninety percent (90%) Hydrogen, with about ten percent (10%) Helium, and only trace amounts of other elements. Stars start out as clouds of dust floating in space. These clouds are not dust as we would usually think of dust, however. They are really just clouds of free-floating elements left over from past stars. As these clouds collapse on themselves, some of the cloud forms a star, while the rest forms things like comets, asteroids, and moons. The amount of each gas can help scientists determine how old the star is, because the gases burn up at different rates.

Chemistry's Role

Astrochemistry and Cosmochemistry are both fields of science devoted to the study of chemicals and reactions in the universe. Stars are constant chemical reactions, whether they are forming, burning, or collapsing all just depends on reactions. Stars shine the brightest, and burn the hottest, when the most chemical reactions are taking place. As the reactions begin to slow, the stars start to collapse, and will eventually become dust clouds once again. Because of amount of elements floating around the universe, there are always stars in every stage of their life.

Background Research

Stars are mostly made up of hydrogen. In the element “dust” clouds in space, different elements are flying around at high speeds. As they slam together, they fuse into one new element. Since hydrogen has only one proton, when they fuse together the new element formed would have two, becoming helium. As each reaction takes place, energy is released in the form of heat and light, creating stars bright enough to be seen from earth.


General information/ main elements

General information/ main elements

General information/ main elements

How stars form/evolve

Star evolution/formation

Info on Astrochemistry

info on Cosmochemistry

About the Author

Randie Marquess is a senior at Billings Senior High School. She enjoys spending time reading, cooking, spending time with her many pets, and most outdoor activities. She likes to spend time camping and looking up at the stars. She will be attending Montana State University in the fall, and majoring in Business.