Summary: An international team of astronomers have detected large amounts of oxygen in the atmosphere of one of the oldest and most primitive stars
Original author and publication date: University of California San Diego – January 24, 2020
Futurizonte Editor’s Note: If there are “large amounts of oxygen” in a star, perhaps there are nearby planets with oxygen. And perhaps there is life on those planets.
From the article:
An international team of astronomers from the University of California San Diego, the Instituto de Astrofísica de Canarias (IAC) and the University of Cambridge have detected large amounts of oxygen in the atmosphere of one of the oldest and most elementally depleted stars known—a primitive star scientists call “J0815+4729.” This new finding, reported in The Astrophysical Journal Letters, provides an important clue about how oxygen and other important elements were produced in the universe’s first generations of stars.
After hydrogen and helium, oxygen is the third most abundant element in the universe and important to all life forms on Earth. It serves as a chemical basis of respiration and a building block of carbohydrates, as well as the main element in the Earth’s crust. Absent from the early universe, it emerged through nuclear fusion reactions that occurred deep inside the most massive stars—stars roughly 10 times or more massive than the sun.
To trace this early production of oxygen and other elements, astronomers study the oldest existing stars. J0815+4729 is one of them. It was first discovered by the IAC team in 2017 using the Grand Canary Telescope in La Palma, in the Canaries, Spain. It resides over 5,000 light years away toward the constellation Lynx.
“Stars like J0815+4729 are referred to as halo stars,” explained UC San Diego Professor of Physics Adam Burgasser, a co-author of the study. “This is due to their roughly spherical distribution around the Milky Way, as opposed to the more familiar flat disk of younger stars that include the sun.”
Halo stars like J0815+4729 are truly ancient stars, allowing astronomers a peek into the universe’s early history of element production. The research team observed J0815+4729 with the W. M. Keck Observatory’s Keck I 10-meter telescope on Mauna Kea, Hawaii, using a high resolution spectrograph called HIRES. The data, which required more than five hours of staring at the star over a single night, were used to measure the abundances of 16 chemical species in the star’s atmosphere, including oxygen.
“The primitive composition of the star indicates that it was formed during the first hundreds of millions of years after the Big Bang, possibly from the material expelled from the first supernovae of the Milky Way,” said Jonay González Hernández, an IAC Ramón y Cajal postdoctoral researcher and lead author of the study.
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