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Rotation Effects as Possible Responsible for the Surface Effects on the Sun and Solar-Type Stars ; ; Reese, Daniel et al in Suárez, Juan Carlos; Garrido, Rafael; Balona, Luis A. (Eds.) et al Stellar Pulsations (2013) One of the main sources of uncertainty in the asteroseismic models of the Sun and solar-like stars is the poor match between predicted oscillation frequencies and observed ones in the very high frequency ... [more ▼] One of the main sources of uncertainty in the asteroseismic models of the Sun and solar-like stars is the poor match between predicted oscillation frequencies and observed ones in the very high frequency domain. Today, effects of turbulence, diffusion, etc., i.e., the so-called "surface effects" are signaled as possible responsible for such a discrepancy. We show that the effect of the stellar deformation due to rotation is of the same order or even larger than these effects. We show that rotation effects, are important for the asteroseismic analysis of the Sun and solar-like stars and they cannot be neglected when modeling such stars. [less ▲] Detailed reference viewed: 17 (2 ULg)2D Computations of g-modes in Fast Rotating Stars ; ; et al in Shibahashi, H; Takata, M; Lynas-Gray, A. E. (Eds.) Progress in Solar/Stellar Physics with Helio- and Asteroseismology (2012, September 01) We present complete 2D computations of g-modes in distorted polytropic models of stars performed with the Two-dimensional Oscillation Program (TOP). We computed low-degree modes (ℓ =1 modes with radial ... [more ▼] We present complete 2D computations of g-modes in distorted polytropic models of stars performed with the Two-dimensional Oscillation Program (TOP). We computed low-degree modes (ℓ =1 modes with radial order n = -1,…,-14, and ℓ = 2, 3 modes with n = -1,…,-5 and -16,…,-20) of a non-rotating model and followed them by slowly increasing the rotation rate up to 70 % of the Keplerian break-up velocity. We use these computations to determine the domain of validity of perturbative methods up to the 3rd order. We study the evolution of the regularities of the spectrum and show quantitative agreement with the traditional approximation for not too large values of the ratio of the rotation rate to the pulsation frequency. We also show the appearance of new types of modes, called “rosette” modes due to their spatial structure. Thanks to the ray theory for gravito-inertial waves that we developed, we can associate these modes with stable periodic rays. [less ▲] Detailed reference viewed: 20 (7 ULg)Rotation on the oscillation spectrum of solar-like stars ; ; Reese, Daniel et al in Alecian, G.; Belkacem, K.; Samadi, R. (Eds.) et al SF2A-2011: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics (2011, December 01) One of the main sources of uncertainty in the asteroseismic models of solar-like stars is the poor match between predicted oscillation frequencies and observed ones in the very high frequency domain ... [more ▼] One of the main sources of uncertainty in the asteroseismic models of solar-like stars is the poor match between predicted oscillation frequencies and observed ones in the very high frequency domain. Today, such deviation is usually corrected by fitting the affected frequencies with polynomials which are then physically explained by possible effects of turbulence, diffusion, etc., i.e., the so-called ``surface effects". In this work, we show that the effect of the stellar deformation due to rotation is of the same order or even larger than the aforementioned surface effects. Moreover, we show that rotation effects, even for the low velocities generally observed in solar-like stars, becomes important for the asteroseismic analysis and cannot be neglected when modeling such stars. [less ▲] Detailed reference viewed: 14 (1 ULg)The Seismology Programme of CoRoT ; ; et al in Proceedings of "The CoRoT Mission Pre-Launch Status - Stellar Seismology and Planet Finding (2006, November 01) We introduce the main lines and specificities of the CoRoT Seismology Core Programme. The development and consolidation of this programme has been made in the framework of the CoRoT Seismology Working ... [more ▼] We introduce the main lines and specificities of the CoRoT Seismology Core Programme. The development and consolidation of this programme has been made in the framework of the CoRoT Seismology Working Group. With a few illustrative examples, we show how CoRoT data will help to address various problems associated with present open questions of stellar structure and evolution. [less ▲] Detailed reference viewed: 61 (34 ULg) |
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