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Thorium-rich halo star HD221170: further evidence against the universality of the r-process

Alexander Yushchenko·Vera Gopka·Stephane Goriely·Faig Musaev·Angelina Shavrina·Chulhee Kim·Young Woon Kang·Juliana Kuznietsova·Vladimir Yushchenko
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Abstract

We report the abundance determination in the atmosphere of the bright halo star HD221170. The spectra were taken with the Terskol Observatory's 2.0-m telescope with a resolution R=45000 and signal-to-noise ratio up to 250 in the wavelength region 3638-10275 Å. The adopted atmospheric parameters correspond to an effective temperature \Tef=4475 K, a surface gravity \lgg=1.0, a microturbulent velocity \vmi=1.7 \kms, and a macroturbulent velocity \vma=4 \kms. The abundances of 43 chemical elements were determined with the method of spectrum synthesis. The large overabundances (by 1 dex relative to iron) of elements with Z$>38$ are shown to follow the same pattern as the solar r-abundances. The present HD221170 analysis confirms the non-universality of the r-process, or more exactly the observation that the astrophysical sites hosting the r-process do not always lead to a unique relative abundance distribution for the bulk Ba to Hg elements, the Pb-peak elements, and the actinides.

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Alexander Yushchenko, Vera Gopka, Stephane Goriely, Faig Musaev, Angelina Shavrina, Chulhee Kim, Young Woon Kang, Juliana Kuznietsova, Vladimir Yushchenko. 2004-09-22. Thorium-rich halo star HD221170: further evidence against the universality of the r-process. https://doi.org/10.1051/0004-6361%3A20041540

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