English
Related papers

Related papers: Solar-like oscillations in semiregular variables

200 papers

Acoustic power and oscillation amplitudes of radial oscillations computed for a solar model are compared with solar seismic observations. The oscillations are assumed stochastically excited by turbulence. The numerical computations are…

Astrophysics · Physics 2009-11-06 Reza Samadi , Marie-Jo Goupil , Yveline Lebreton

In solar-like oscillators, acoustic waves are excited by turbulent motion in the convective envelope and propagate inward, generating a variety of standing pressure modes. When combining together the power of several solar acoustic modes,…

Solar and Stellar Astrophysics · Physics 2025-08-27 E. Panetier , R. A. García , S. N. Breton , A. Jiménez , T. Foglizzo

Over the past decade the study of solar-like oscillations in red-giant stars has developed significantly. Not only the number of red-giant stars for which solar-like oscillations have been observed has increased, but the quality of these…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. Hekker

Motivated by the recent detection of stochastically excited modes in the massive star V1449 Aql (Belkacem et al., 2009b), already known to be a $\beta$ Cephei, we theoretically investigate the driving by turbulent convection. By using a…

Solar and Stellar Astrophysics · Physics 2015-05-14 K. Belkacem , M. A. Dupret , A. Noels

Seismology of stars provides insight into the physical mechanisms taking place in their interior, with modes of oscillation probing different layers. Low-amplitude acoustic oscillations excited by turbulent convection were detected four…

Solar quasi-biennial oscillations with period range 0.6 to 4 years, are prominent in records of solar activity. Here we show that the 1.6 year quasi-biennial oscillation in solar activity has the exceptional feature of phase inversion…

Solar and Stellar Astrophysics · Physics 2021-10-27 Ian R. Edmonds

In this short review on stellar convection dynamics I address the following, currently very topical, issues: (1) the surface effects of the Reynolds stresses and nonadiabaticity on solar-like pulsation frequencies, and (2) oscillation mode…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Houdek

Despite more and more observational data, stellar acoustic oscillation modes are not well understood as soon as rotation cannot be treated perturbatively. In a way similar to semiclassical theory in quantum physics, we use acoustic ray…

Solar and Stellar Astrophysics · Physics 2011-09-16 M. Pasek , B. Georgeot , F. Lignieres , D. R. Reese

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

Astrophysics · Physics 2009-10-31 Å. Nordlund , R. F. Stein

Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? We investigate under what…

We present estimates of the amplitudes of intrinsically stable stochastically excited radial oscillations in stars near the main sequence. The amplitudes are determined by the balance between acoustical energy generation by turbulent…

Astrophysics · Physics 2007-05-23 G. Houdek , N. J. Balmforth , J. Christensen-Dalsgaard , D. O. Gough

Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…

Solar and Stellar Astrophysics · Physics 2023-05-31 J. Philidet , L. Gizon

An overview of selected topical problems on modelling oscillation properties in solar-like stars is presented. High-quality oscillation data from both space-borne intensity observations and ground-based spectroscopic measurements provide…

Solar and Stellar Astrophysics · Physics 2011-03-28 Gunter Houdek

We have made velocity observations of the star alpha Cen B from two sites, allowing us to identify 37 oscillation modes with l=0-3. Fitting to these modes gives the large and small frequency separations as a function of frequency. The mode…

The solar torsional oscillations, i.e., the perturbations of the angular velocity of rotation associated with the eleven-year activity cycle, are a manifestation of the interaction among the interior magnetic fields, amplified and modulated…

Astrophysics · Physics 2009-11-13 Antonino F. Lanza

There are no good predictions for the amplitudes expected from solar-like oscillations in other stars. In the absence of a definitive model for convection, which is thought to be the mechanism that excites these oscillations, the amplitudes…

Astrophysics · Physics 2011-05-05 H. Kjeldsen , T. R. Bedding

Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…

Solar and Stellar Astrophysics · Physics 2019-07-09 S. Mathur , J. Ballot , R. A. Garcia

The amplitudes of solar-like oscillations depend on the excitation and damping, both of which are controlled by convection. Comparing observations with theory should therefore improve our understanding of the underlying physics. However,…

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different…

Solar and Stellar Astrophysics · Physics 2016-01-18 Günter Houdek , Marc-Antoine Dupret

Solar p-mode oscillations are excited by the work of stochastic, non-adiabatic, pressure fluctuations on the compressive modes. We evaluate the expression for the radial mode excitation rate derived by Nordlund and Stein (Paper I) using…

Astrophysics · Physics 2009-10-31 R. F. Stein , Å. Nordlund