Thorium-rich halo star HD 221170: Further evidence against the universality of the r-process ^*,**

¹ Astrophysical Research Center for the Structure and Evolution of the Cosmos (ARCSEC), Sejong University, Seoul 143-747, Korea e-mail: yua@arcsec.sejong.ac.kr; kangyw@sejong.ac.kr
² Odessa Astronomical observatory, Odessa National University, Park Shevchenko, Odessa 65014, Ukraine e-mail: yua@odessa.net; gopka@arctur.tenet.odessa.ua
³ Institut d'Astronomie et d'Astrophysique, Université Libre de Bruxelles, CP 226, 1050 Brussels, Belgium e-mail: sgoriely@astro.ulb.ac.be
⁴ Special Astrophysical observatory of the Russian Academy of Sciences, Nizhnij Arkhyz, Zelenchuk, Karachaevo-Cherkesiya 369167, Russia e-mail: faig@sao.ru
⁵ The International Centre for Astronomical, Medical and Ecological Research of the Russian Academy of Sciences and the National Academy of Sciences of Ukraine, Golosiiv, Kiev 03680, Ukraine e-mail: admin@terskol.com
⁶ Shamakhy Astrophysical Observatory, NAS of Azerbaijan, Yusif Mamedaliev, Shamakhy, Azerbaijan
⁷ Main Astronomical observatory, NAS of Ukraine, Kiiv 03680, Ukraine e-mail: shavrina@mao.kiev.ua
⁸ Department of Earth Science Education, Chonbuk National University, Chonju 561-756, Korea e-mail: chkim@astro.chonbuk.ac.kr
⁹ Odessa National University, Odessa 65014, Ukraine e-mail: yushchenko@mail.ru

Received: 4 March 2004
Accepted: 8 September 2004

Abstract

We report the abundance determination in the atmosphere of the bright halo star HD 221170. The spectra were taken with the Terskol Observatory's 2.0-m telescope with a resolution 45 000 and signal-to-noise ratio up to 250 in the wavelength region 3638–10 275 Å. The adopted atmospheric parameters correspond to an effective temperature  = 4475 K, a surface gravity  = 1.0, a microturbulent velocity  = 1.7 , and a macroturbulent velocity  = 4 . 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 HD 221170 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.