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Ancient Stars Older Than the Milky Way Found at the Center of Our Galaxy

11/13/2015 09:22AM

Ancient Stars Older Than the Milky Way Found at the Center of Our Galaxy

An international team of astronomers, led by researchers from the University of Cambridge and the Australian National University, have discovered some of the oldest stars in our galaxy, whose chemical composition and movements could tell us what the Universe was like soon after the Big Bang. These stars, which have been at the very center of the Milky Way for billions of years, contain extremely low amounts of metal and are made up almost entirely of hydrogen, helium, and small amounts of lithium.


Comments:

  • 1953 [Jeff Blazey]
  • 11/18/2015 07:00AM
As I understand it, older stars are also lower in mass. Or maybe that general rule breaks down when a star has a low metal content. The article does not comment on their mass.<br><br>Jeff
<br>Jeff:<br><br>Yes -- I believe you are correct.<br><br>According to Kam-Ching Leung, Professor of Physics and Astronomy at the University of Nebraska - Lincoln:<br><br>"Low-mass stars consume themselves at a slower rate than more massive stars. In its entire lifetime, the conversion of a small-mass star's elemental fuel may go no farther than helium. More massive stars burn hotter and faster, and may end their lifetimes with a core fueled by elements as heavy as carbon or iron. We look at a star and see how its chemistry changes. All of the original stars in the universe were created at about the same time. How long they live depends on their conversion rates -- how fast nuclear fusion changes their fuel from one chemical to another. The conversion rate is dependent on high orders of interior temperature, and temperature is strongly dependent on mass."<br><br>http://astro.unl.edu/observatory/art3a.html<br><br><br>Hope this helps,<br><br>Guy Pirro<br><br><br><blockquote class="blockquote"><div class="italic"><i>Jeff Blazey said:</i><br><br>As I understand it, older stars are also lower in mass. Or maybe that general rule breaks down when a star has a low metal content. The article does not comment on their mass.<br><br>Jeff</div></blockquote>