Nonradial Mode Excitation as the Cause of the Blazhko Effect in RR Lyrae Stars

• Autorzy: Dziembowski W. A. , Mizerski T.
• Języki publikacji: EN

Abstrakty

EN

A significant fraction of RR Lyr stars exhibits amplitude and/or phase modulation known as the the Blazhko effect. The oscillation spectra suggest that, at least in most of the cases, excitation of a nonradial modes in addition to the dominant radial modes is responsible for the effect. Though model calculations predict that nonradial modes may be excited, there are problems with explaining their observed properties in terms of finite amplitude development of the linear instability. We propose a scenario, which like some previous, postulates energy transfer from radial to nonradial modes, but avoids those problems. The scenario predicts lower amplitudes in Blazhko stars. We check this prediction with a new analysis of the Galactic bulge RR Lyr stars from OGLE-II database. The effect is seen, but the amplitude reduction is smaller than predicted.

Słowa kluczowe

EN

stars: oscillations; stars: variables: RR Lyr

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2004
• Tom: Vol. 54, No. 4
• Strony: 363--373
• Opis fizyczny: Bibliogr. 19 poz., tab., wykr.

Twórcy

autor

Dziembowski W. A.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
• Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Mizerski T.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

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