EDP Sciences
Free Access
Volume 377, Number 2, October II 2001
Page(s) L22 - L25
Section Letters
DOI https://doi.org/10.1051/0004-6361:20011179

A&A 377, L22-L25 (2001)
DOI: 10.1051/0004-6361:20011179

Pulsational and rotational line profile variations of the roAp stars $\alpha$ Cir and HR 3831

O. Kochukhov1 and T. Ryabchikova2, 3

1  Uppsala Astronomical Observatory, Box 515, S-751 20 Uppsala, Sweden
    e-mail: oleg@astro.uu.se
2  Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya 48, 109017 Moscow, Russia
    e-mail: ryabchik@inasan.rssi.ru
3  Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
    e-mail: ryabchik@tycho.astro.univie.ac.at

(Received 19 July 2001 / Accepted 22 August 2001 )

We report preliminary results of our new time-resolved high-resolution spectroscopic observations of the roAp stars $\alpha$ Cir and HR 3831. Analysis of pulsational behaviour of individual spectral lines in the 6116-6156 Åspectral region revealed that in both stars it is dominated by the strong rapid variations of the NdIII 6145.07 Åspectral line. Oscillations of the NdIII spectral feature are also rotationally modulated. In addition we observed strong rotational modulation of the average HR 3831 line profiles caused by abundance spots on the stellar surface. Weaker rotational modulation was also discovered for the metal lines in the $\alpha$ Cir spectrum. This variability agrees with the rotational period of $\alpha$ Cir obtained from the splitting of the principal pulsation frequency.

Key words: stars: chemically peculiar -- stars: oscillations -- stars: individual: $\alpha$ Cir, HR 3831

Offprint request: O. Kochukhov, oleg@astro.uu.se

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