CAOSP abstracts, Volume: 38, No.: 2, year: 2008

Author(s): Kochukhov, O; Ryabchikova, T.; Bagnulo, S.; Lo Curto, G.
Journal: Contributions of the Astronomical Observatory Skalnaté Pleso, vol. 38, no. 2, p. 423-424.
Date: 4/2008
Title: A search for very low amplitude magnetoacoustic pulsations with HARPS
Keyword(s): stars: atmospheres, stars: chemically peculiar, stars: oscillations, stars: individual: HD 75445, HD 137909
Pages: 423 -- 424

Abstract: We have obtained time-resolved spectroscopic observations for a sample of 10 cool Ap stars using the ultra-stable spectrograph HARPS at the ESO 3.6 m telescope. The aim of our study was to search for low-amplitude oscillations in Ap stars with no or inconclusive evidence of pulsational variability. Here we report initial results of our investigation. We confirm the presence of ≈ 16 min period pulsations in β CrB (HD 137909) and demonstrate multiperiodic character of oscillations in this star. Furthermore, we discovered very low amplitude 9-min pulsations in HD 75445 - an object spectroscopically very similar to known roAp stars.

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