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Paper: |
Spectroscopy of the Extremely Metal-Poor Red Giant HE 0056-3022 |
Volume: |
497, Why Galaxies Care about AGB Stars III: A Closer Look in Space and Time |
Page: |
309 |
Authors: |
Klavins, A.; Barzdis, A.; Smirnova, O. |
Abstract: |
Among the oldest objects in the Universe, metal-poor stars can be used
to test stellar evolution in the early Universe. Detailed analysis of
such stars can provide important data for stellar astrophysics and
cosmology as well. This research is based on high-resolution
spectroscopy of the poorly studied extremely metal-poor star
HE 0056-3022. The results for its chemical composition and
atmospheric parameters are collected and analysed, and the possible
evolutionary status of the star and the source of its chemical
peculiarities are reviewed. Our derived iron abundance,
[Fe/H] = –3.25 dex, shows that HE 0056-3022 is extremely
metal-poor. From analysis of the abundances obtained for other
elements we conclude that the star most likely is on the Red Giant
Branch (RGB) and is experiencing a Helium core burning flash. The
atmosphere of the star is abundant in α-elements, especially
oxygen with [O/Fe] = +1.45. These elements mainly form in Type II
supernova explosions. The possible binary origin of the star is also
mentioned. |
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