Oxygen is the element with atomic number 8, symbol O. Its usual isotope has atomic weight 16, but 17 and 18 are also stable.
It results from CNO Cycle and Neon burning.
It is the third most common element. The Milky Way is about 1% Oxygen by mass.
Asymptotic Giant Branch (AGB)
Carbon Monoxide (CO)
Carbon Dioxide (CO2)
Energetic Neutral Atom (ENA)
Triple Alpha Process
Type Ia Supernova