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Related papers: Diagnostics from solar and stellar glitches

200 papers

Helioseismic inversions for the rotation rate have established the presence of a tachocline near the base of the solar convection zone. We show that the tachocline produces a characteristic oscillatory signature in the splitting…

Astrophysics · Physics 2009-11-06 Anwesh Mazumdar , H. M. Antia

In the past decade, helioseismology has revolutionized our understanding of the interior structure of the Sun. In the next decade, asteroseismology will place this knowledge into context, by providing structural information for dozens of…

Astrophysics · Physics 2007-05-23 T. S. Metcalfe , T. M. Brown , J. Christensen-Dalsgaard

Mixing processes such as convection, overshooting and rotational mixing have long been known to affect the evolutionary properties of low-mass stars. While modeling a 1.2 Msun star, we encountered a semiconvective region outside the fully…

Solar and Stellar Astrophysics · Physics 2015-05-14 V. Silva Aguirre , J. Ballot , A. Serenelli , A. Weiss

Convection is ubiquitous in stars and occurs under many different conditions. Here we explore convection in main-sequence stars through two lenses: dimensionless parameters arising from stellar structure and parameters which emerge from the…

Solar and Stellar Astrophysics · Physics 2022-08-31 Adam S. Jermyn , Evan H. Anders , Daniel Lecoanet , Matteo Cantiello

Dissipative phenomena occurring during the orbital evolution of a dwarf satellite galaxy around a host galaxy may leave signatures in the star formation activity and signatures in the colour magnitude diagram of the galaxy stellar content.…

Astrophysics of Galaxies · Physics 2015-06-04 S. Pasetto , G. Bertelli , E. K. Grebel , C. Chiosi , Y. Fujita

Spectral-line displacements away from the wavelengths naively expected from the Doppler shift caused by stellar radial motion may originate as convective shifts (correlated velocity and brightness patterns in the photosphere), as…

Astrophysics · Physics 2007-05-23 D. Dravins , L. Lindegren , H. -G. Ludwig , S. Madsen

The interstellar medium of galaxies is composed of multiple phases, including molecular, atomic, and ionized gas, as well as dust. Stars are formed within this medium from cold molecular gas clouds, which collapse due to their gravitational…

Astrophysics of Galaxies · Physics 2024-06-03 Jonathan Freundlich

In the present paper, we aim to constrain the properties of the ionisation region in a star from the oscillation frequency variation (a so-called glitch) caused by rapid structural variations in this very region. In particular, we seek to…

Solar and Stellar Astrophysics · Physics 2022-07-13 Pierre S. Houdayer , Daniel R. Reese , Marie-Jo Goupil

In many evolutionary stages, low- and intermediate-mass stars show signs of mixing of the surface material with material from the interior. To account for all the details revealed by the observations it is necessary to include non-standard…

Solar and Stellar Astrophysics · Physics 2011-07-01 Rodolfo Smiljanic

We use a seismic diagnostic, based on the derivative of the phase shift of the reflected by the surface acoustic waves, to probe the outer layers of the star HD 49933. This diagnostic is particularly sensitive to partial ionization…

Solar and Stellar Astrophysics · Physics 2016-12-16 Ana Brito , Ilídio Lopes

During most of their life, stars fuse hydrogen into helium in their cores. The mixing of chemical elements in the radiative envelope of stars with a convective core is able to replenish the core with extra fuel. If effective, such deep…

The solar interior has been scrutinized by two different and independent probes during the last twenty years with important revisions of the solar model, including a recent heavy element abundance revision. Today, we get a quantitatively…

Astrophysics · Physics 2009-11-11 S. Turck-Chieze , S. Couvidat , L. Piau

Solar-like oscillations are stochastically excited by turbulent convection. In this work we investigate changes in the acoustic oscillation power spectrum of solar-type stars by varying the treatment of convection in the equilibrium…

Astrophysics · Physics 2007-05-23 Reza Samadi , Guenter Houdek , Marie-Jo Goupil , Yveline Lebreton , Annie Baglin

Sharp structural variations induce specific signatures on stellar pulsations that can be studied to infer localised information on the stratification of the star. This information is key to improve our understanding of the physical…

Internal gravity waves (IGWs) can cause mixing in the radiative interiors of stars. We study this mixing by introducing tracer particles into two - dimensional (2D) hydrodynamic simulations. Following the work of Rogers & McElwaine (2017),…

Solar and Stellar Astrophysics · Physics 2023-01-18 A. Varghese , R. P. Ratnasingam , R. Vanon , P. V. F. Edelmann , T. M. Rogers

Star clusters stand at the intersection of much of modern astrophysics: the interstellar medium, gravitational dynamics, stellar evolution, and cosmology. Here we review observations and theoretical models for the formation, evolution, and…

Astrophysics of Galaxies · Physics 2019-09-11 Mark R. Krumholz , Christopher F. McKee , Joss Bland-Hawthorn

The element settling due to the combined effects of gravity, thermal gradient, radiative acceleration and concentration gradient may lead to important abundance variations inside the stars, which cannot be neglected in the computations of…

Astrophysics · Physics 2007-05-23 Sylvie Vauclair

We have identified an important source of mixing in stellar radiation zones, that would arise whenever two conditions are satisfied: (1) the presence of an inverse vertical compositional gradient, and (2) the presence of…

Solar and Stellar Astrophysics · Physics 2015-06-22 Michael Medrano , Pascale Garaud , Stephan Stellmach

Modeling properly the interface between convective cores and radiative interiors is one the most challenging and important open questions in modern stellar physics. The rapid development of asteroseismology, with the advent of space…

Solar and Stellar Astrophysics · Physics 2020-01-14 S. Deheuvels

Stellar nucleosynthesis is the corner-stone of many astrophysical problems. Its understanding, which can be tested by countless observations, leads to insights into the stellar structure and evolution, and provides crucial clues to the…

Astrophysics · Physics 2007-05-23 C. Charbonnel