Astronomers have discovered an ancient star has an unusual atmosphere, which just may give us a clue how oxygen became so abundant in the cosmos.

Researchers from institutes across the world including the University of California San Diego, the Instituto de Astrofísica de Canarias (IAC), and the University of Cambridge have examined the atmosphere of a ‘primitive star’ — J0815+4729 located 5k light-years from Earth— discovering an abundance of oxygen. The finding, reported in The Astrophysical Journal Letters, comes as something of a surprise because as one of the first stars to form in the universe, J0815+4729 is one of the oldest and most elementally depleted stars ever recorded by astronomers.

The research conducted with the aid of the W.M Keck Observatory located on Maunakea in Hawaii consists of am analysis of the chemical make-up of the ancient star, providing, in-turn, a clue as to how oxygen and other vital elements were created within the universe’s first generation of stars.

Artistic image of the supernova explosions of the first massive stars that formed in the Milky Way. The star j0815+4729 was formed from the material ejected by these first supernovae. ( Gabriel Pérez, SMM (IAC))

“This result is very exciting. It tells us about some of the earliest times in the universe by using stars in our cosmic back yard,” says John O’Meara, Keck Observatory Chief Scientist. “I look forward to seeing more measurements like this one so we can better understand the earliest seeding of oxygen and other elements throughout the young universe.”

J0815+4729 is a ‘halo star’, part of a population of stars that is truly ancient and as such, it is able to give astronomers a vital glimpse into the production of elements more massive than helium — which astronomers refer to as ‘metals’ — in the early universe.