EDP Sciences
Free access
Volume 372, Number 2, June III 2001
Page(s) 571 - 578
Section Formation, structure and evolution of stars
DOI http://dx.doi.org/10.1051/0004-6361:20010506

A&A 372, 571-578 (2001)
DOI: 10.1051/0004-6361:20010506

Lithium on the surface of cool magnetic CP stars. II. Spectrum analysis of HD 83368 and HD 60435 with lithium spots

A. V. Shavrina1, N. S. Polosukhina2, J. Zverko3, L. I. Mashonkina4, V. Khalack1, J. Ziznovský3, M. Hack5, V. Tsymbal6, P. North7 and V. V. Vygonec4

1  Main Astronomical Observatory, National Academy of Sciences, Kiev 03680, Ukraine,
    e-mail: name@mao.kiev.ua
2  Crimean Astrophysical Observatory, Nauchnyj, Ukraine,
    e-mail: polo@crao.crimea.ua
3  Astronomical Institute, Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovakia,
    e-mail: name@ta3.sk
4  Kazan State University, Kazan 420008, Russia,
    e-mail: name@ksu.ru
5  Dept. of Astronomy, Trieste Univ., 34131 Trieste, Italy,
    e-mail: hack@ts.astro.it
6  Simpheropol State University, Simpheropol 330000, Ukraine,
    e-mail: VAD@ccssu.crimea.ua
7  Inst. d'Astronomie, Univ. Lausanne, 1290 Chavannes-des-Bois, Switzerland,
    e-mail: Pierre.North@obs.unige.ch

(Received 31 May 2000 / Accepted 2 April 2001 )

As a further step in our Lithium project we present results of abundance determination of some elements in the roAp star HD 60435. Possible NLTE effects were considered. Equivalent widths of spectral lines vary with rotational phase which suggests nonuniform distribution of chemical elements over the stars' surface. Large abundance differences derived from various ions of some rare earth elements indicate their possible vertical stratification. Two spots of enhanced lithium abundance were distinguished at the magnetic poles on HD 60435 and their parameters derived. The rotational axis inclination $i=133^\circ$ or $47^\circ$ and surface magnetic field $H_{\rm s}=3 \pm 1$ kG were determined for the first time for HD 60435. The results are compared with HD 83368, the other star with lines of lithium remarkably variable in intensity and wavelength.

Key words: stars: individual: HD 83368, HD 60435 -- stars: abundances -- stars: chemically peculiar -- stars: magnetic field

Offprint request: A. V. Shavrina, name@mao.kiev.ua

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