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Related papers: Did Kepler-444 have a long-lived convective core?

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Stellar rotation on the main sequence is a complex function of mass and age, displaying multiple regimes whose physical origin remains only partially understood. In particular, the connection between the diversity of observed rotation rates…

Solar and Stellar Astrophysics · Physics 2026-05-13 Ana Brito , Ilídio Lopes

The chemical composition of stars hosting small exoplanets (with radii less than four Earth radii) appears to be more diverse than that of gas-giant hosts, which tend to be metal-rich. This implies that small, including Earth-size, planets…

Recent photometric observations of massive stars have identified a low-frequency power excess which appears as stochastic low-frequency variability in light curve observations. We present the oscillation properties of high resolution…

Solar and Stellar Astrophysics · Physics 2024-05-01 William Thompson , Falk Herwig , Paul R. Woodward , Huaqing Mao , Pavel Denissenkov , Dominic M. Bowman , Simon Blouin

In this paper, four sets of evolutionary models are computed with different values of the mixing length parameter $\alpha_{\rm p}$ and the overshooting parameter $\delta_{\rm ov}$. The properties of the convective cores and the convective…

Solar and Stellar Astrophysics · Physics 2015-05-14 Jin Jie , Chunhua Zhu , Guoliang Lv

In this paper, we present the results of CARMA continuum and spectral line observations of the dense core Per-Bolo 45. Although this core has previously been classified as starless, we find evidence for an outflow and conclude that Per-Bolo…

Astrophysics of Galaxies · Physics 2015-06-03 Scott Schnee , James Di Francesco , Melissa Enoch , Rachel Friesen , Doug Johnstone , Sarah Sadavoy

Solar-like oscillations are expected to be excited in stars of up to about 1.6 solar masses. Most of these stars will have convective cores during their Main-sequence evolution. At the edges of these convective cores there is a rapid…

Solar and Stellar Astrophysics · Physics 2015-05-19 Margarida S. Cunha , Isa M. Brandão

In stellar evolution calculations, the local pressure scale height is often used to empirically constrain the amount of convective core overshoot. However, this method brings unsatisfactory results for low-mass stars (< 1.1 -1.2 Mo for Z=…

Astrophysics · Physics 2009-11-06 Jong-Hak Woo , Pierre Demarque

We propose a methodological framework to perform forward asteroseismic modeling of stars with a convective core, based on gravity-mode oscillations. These probe the near-core region in the deep stellar interior. The modeling relies on a set…

We investigate the variability properties of main sequence stars in the first month of Kepler data, using a new astrophysically robust systematics correction, and find that 60% of stars are more variable then the active Sun. We define low…

Solar and Stellar Astrophysics · Physics 2013-10-24 Amy McQuillan , Suzanne Aigrain , Stephen Roberts

We have performed survey-type observations in 1 mm continuum and molecular lines toward dense cores (32 prestellar + 7 protostellar) with an average density of $\gtrsim$10$^5$ cm$^{-3}$ in the Taurus molecular clouds using the Atacama Large…

The advent of massively parallel supercomputing has begun to permit explicit 3--D simulations of turbulent convection occurring within the cores of early-type main sequence stars. Such studies should complement the stellar structure and…

Astrophysics · Physics 2007-05-23 Allan Sacha Brun , Matthew Browning , Juri Toomre

Asteroseismic modelling of the internal structure of main-sequence stars born with a convective core has so far been based on homogeneous analyses of space photometric Kepler light curves of 4 years duration, to which most often incomplete…

Convection is a fundamental physical process in the fluid cores of planets because it is the primary transport mechanism for heat and chemical species and the primary energy source for planetary magnetic fields. Key properties of…

Geophysics · Physics 2019-09-11 Céline Guervilly , Philippe Cardin , Nathanaël Schaeffer

In the context of the determination of stellar properties using asteroseismology, we study the influence of rotation and convective-core overshooting on the properties of red-giant stars. We used models in order to investigate the effects…

Solar and Stellar Astrophysics · Physics 2015-12-14 Nadège Lagarde , Diego Bossini , Andrea Miglio , Mathieu Vrard , Benoit Mosser

Useful information from the inner layers of stellar pulsators may be derived from the study of their oscillations. In this paper we analyse three diagnostic tools suggested in the literature built from the oscillation frequencies computed…

Solar and Stellar Astrophysics · Physics 2015-05-19 I. M. Brandão , M. S. Cunha , O. L. Creevey , J. Christensen-Dalsgaard

Successful inference from asteroseismology relies on at least two things: that the oscillations in the stars have amplitudes large enough to be clearly observable; and that the oscillations themselves be stable enough to enable precise…

Solar and Stellar Astrophysics · Physics 2015-05-13 W. J. Chaplin , G. Houdek , C. Karoff , Y. Elsworth , R. New

Relying on precise observations for the CPD-54 810 binary system, we investigate the robustness of the estimated age and convective core overshooting for a system with both stars on the main sequence (MS). [...] We adopt the SCEPtER…

Solar and Stellar Astrophysics · Physics 2023-05-24 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

We report on the discovery of an instability in low mass stars just above the threshold ($\sim 0.35 \textrm{M}_{\odot}$) where they are expected to be fully convective on the main sequence. Non-equilibrium He3 burning creates a convective…

Solar and Stellar Astrophysics · Physics 2015-06-03 Jennifer L. van Saders , Marc H. Pinsonneault

Semiconvection - mixing that occurs in regions that are stable when considering compositional gradients, but unstable when ignoring them - is shown to have the greatest potential impact on main sequence stars with masses in the range 1.2 -…

Solar and Stellar Astrophysics · Physics 2016-01-27 Kevin Moore , Pascale Garaud

Starless cores represent the initial stage of evolution toward (proto)star formation, and a subset of them, known as prestellar cores, with high density (~ 10^6 cm^-3 or higher) and being centrally concentrated are expected to be embryos of…