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Related papers: Nonlinear Mixed Modes in Red Giants

200 papers

Asteroseismology is a powerful tool that may be applied to shed light on stellar interiors and stellar evolution. Mixed modes, behaving as acoustic waves in the envelope and buoyancy modes in the core, are remarkable because they allow for…

Solar and Stellar Astrophysics · Physics 2023-10-04 Siddharth Dhanpal , Othman Benomar , Shravan Hanasoge , Masao Takata , Subrata Panda , Abhisek Kundu

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…

Among 19 red-giant stars belonging to eclipsing binary systems that have been identified in Kepler data, 15 display solar-like oscillations. We study whether the absence of mode detection in the remaining 4 is an observational bias or…

Solar and Stellar Astrophysics · Physics 2015-06-18 Patrick Gaulme , Jason Jackiewicz , Thierry Appourchaux , Benoit Mosser

A growing number of solar-like oscillations has been detected in red giant stars thanks to CoRoT and Kepler space-crafts. The seismic data gathered by CoRoT on red giant stars allow us to test mode driving theory in physical conditions…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. Samadi , K. Belkacem , M. -A. Dupret , H. -G. Ludwig , F. Baudin , E. Caffau , M. -J. Goupil , C. Barban

The CoRoT mission has provided thousands of red-giant light curves. The analysis of their solar-like oscillations allows us to characterize their stellar properties. Up to now, the global seismic parameters of the pressure modes remain…

Seismic observations have shown that a number of evolved stars exhibit low-amplitude dipole modes, which are referred to as depressed modes. Recently, these low amplitudes have been attributed to the presence of a strong magnetic field in…

Solar and Stellar Astrophysics · Physics 2017-02-01 B. Mosser , K. Belkacem , C. Pincon , M. Takata , M. Vrard , C. Barban , M-J. Goupil , T. Kallinger , R. Samadi

We discuss properties of oscillatory convective modes in low-mass red giants, and compare them with observed properties of the long secondary periods (LSPs) of semi-regular red giant variables. Oscillatory convective modes are very…

Solar and Stellar Astrophysics · Physics 2015-07-14 Hideyuki Saio , Peter R. Wood , Masaki Takayama , Yoshifusa Ita

There is growing observational evidence that the variability of red giants could be caused by excitation of global modes of oscillation. The most recent evidence of such oscillations was reported for alpha UMa by Buzasi et al.(2000). We…

Astrophysics · Physics 2009-11-07 W. A. Dziembowski , D. O. Gough , G. Houdek , R. Sienkiewicz

A red giant star is an evolved low- or intermediate-mass star that has exhausted its central hydrogen content, leaving a helium core and a hydrogen-burning shell. Oscillations of stars can be observed as periodic dimmings and brightenings…

Solar and Stellar Astrophysics · Physics 2022-10-26 Gang Li , Sébastien Deheuvels , Jérôme Ballot , François Lignières

When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant, in which convection occupies a large fraction of the star.…

We have computed linear non-adiabatic oscillations of luminous red giants using a non-local and anisotropic time-dependent theory of convection. The results show that low-order radial modes can be self-excited. Their excitation is the…

Solar and Stellar Astrophysics · Physics 2018-08-30 D. R. Xiong , L. Deng , C. Zhang

Solar-like oscillations in red giants have been investigated with CoRoT and Kepler, while pulsations in more evolved M giants have been studied with ground-based microlensing surveys. After 3.1 years of observation with Kepler, it is now…

Solar and Stellar Astrophysics · Physics 2015-06-17 B. Mosser , W. A. Dziembowski , K. Belkacem , M. J. Goupil , E. Michel , R. Samadi , I. Soszynski , M. Vrard , E. Elsworth , S. Hekker , S. Mathur

The frequencies of oscillation modes in stars contain valuable information about the stellar properties. In red giants the frequency spectrum also contains mixed modes, with both pressure (p) and gravity (g) as restoring force, which are…

Solar and Stellar Astrophysics · Physics 2017-11-08 Nathalie Themeßl , Saskia Hekker , Yvonne Elsworth

The Kepler space mission provided high-quality light curves for more than 16 000 red giants. The global stellar oscillations extracted from these light curves carry information about the interior of the stars. Several hundred red giants…

Solar and Stellar Astrophysics · Physics 2024-09-20 Quentin Coppée , Jonas Müller , Michaël Bazot , Saskia Hekker

The power of asteroseismology relies on the capability of global oscillations to infer the stellar structure. For evolved stars, we benefit from unique information directly carried out by mixed modes that probe their radiative cores. This…

Solar and Stellar Astrophysics · Physics 2017-03-29 B. Mosser , C. Pinçon , K. Belkacem , M. Takata , M. Vrard

Since the detection of non-radial solar-like oscillation modes in red giants with the CoRoT satellite, the interest in the asteroseismic properties of red giants and the link with their global properties and internal structure is…

Solar and Stellar Astrophysics · Physics 2014-08-22 Josefina Montalbán , Arlette Noels

Mixed modes seen in evolved stars carry information on their deeper layers that can place stringent constraints on their physics and on their global properties (mass, age, etc...). In this study, we present a method to identify and measure…

Solar and Stellar Astrophysics · Physics 2015-06-15 O. Benomar , T. R. Bedding , B. Mosser , D. Stello , K. Belkacem , R. A. Garcia , T. R. White , C. A Kuehn , S. Deheuvels , J. Christensen-Dalsgaard

Sun-like oscillations, that is p-modes excited stochastically by convective noise, have now been observed in a number of Red Giant stars. Compared to those seen in the Sun, these modes are of large amplitude and long period, making the…

Astrophysics · Physics 2008-10-22 N. J. Tarrant , W. J. Chaplin , Y. P. Elsworth , S. A. Spreckley , I. R. Stevens

Stellar models rely on a number of free parameters. High-quality observations of eclipsing binary stars observed by Kepler offer a great opportunity to calibrate model parameters for evolved stars. Our study focuses on six Kepler red giants…

Solar and Stellar Astrophysics · Physics 2018-01-31 Tanda Li , Timothy R. Bedding , Daniel Huber , Warrick H. Ball , Dennis Stello , Simon J. Murphy , Joss Bland-Hawthorn

We report for the first time a parametric fit to the pattern of the \ell = 1 mixed modes in red giants, which is a powerful tool to identify gravity-dominated mixed modes. With these modes, which share the characteristics of pressure and…