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Particular diagnostic tools may isolate the signature left on the oscillation frequencies by the presence of a small convective core. Their frequency derivative is expected to provide information about convective core's properties and…

Solar and Stellar Astrophysics · Physics 2015-06-18 I. M. Brandão , M. S. Cunha , J. Christensen-Dalsgaard

High-precision photometric observations have revealed ubiquitous stochastic low-frequency photometric variability in early type stars. It has been suggested that this variability arises due to either subsurface convection or internal…

Solar and Stellar Astrophysics · Physics 2022-03-02 Matteo Cantiello , Daniel Lecoanet , Adam S. Jermyn , Luca Grassitelli

Bowman et al. (2019) reported low-frequency photometric variability in 164 O- and B-type stars observed with K2 and TESS. They interpret these motions as internal gravity waves, which could be excited stochastically by convection in the…

The relation of period spacing ($\Delta P$) versus period ($P$) of dipole prograde g modes is known to be useful to measure rotation rates in the g-mode cavity of rapidly rotating $\gamma$ Dor and slowly pulsating B (SPB) stars. In a…

Solar and Stellar Astrophysics · Physics 2021-03-03 Hideyuki Saio , Masao Takata , Umin Lee , Gang Li , Timothy Van Reeth

Some physical processes that occur during a star's main-sequence evolution also affect its post main-sequence evolution. It is well known that stars with masses above approximately 1.1 $M_{\odot}$ have well-mixed convective cores on the…

Solar and Stellar Astrophysics · Physics 2024-02-21 Christopher J. Lindsay , J. M. Joel Ong , Sarbani Basu

Observations indicate that the convective cores of stars must ingest a substantial amount of material from the overlying radiative zone, but the extent of this mixing and the mechanism which causes it remain uncertain. Recently, Anders et…

Solar and Stellar Astrophysics · Physics 2022-05-11 Adam S. Jermyn , Evan H. Anders , Daniel Lecoanet , Matteo Cantiello

The transition between convective and radiative stellar regions is still not fully understood. The sharp variations in sound speed located in these transition regions give rise to a signature in specific seismic indicators, opening the…

Solar and Stellar Astrophysics · Physics 2023-05-10 M. Deal , M. -J. Goupil , M. S. Cunha , M. J. P. F. G. Monteiro , Y. Lebreton , S. Christophe , F. Pereira , R. Samadi , A. V. Oreshina , G. Buldgen

Our poor understanding of the boundaries of convective cores generates large uncertainties on the extent of these cores and thus on stellar ages. Our aim is to use asteroseismology to consistently measure the extent of convective cores in a…

Solar and Stellar Astrophysics · Physics 2016-04-20 S. Deheuvels , I. Brandão , V. Silva Aguirre , J. Ballot , E. Michel , M. S. Cunha , Y. Lebreton , T. Appourchaux

Recent observations of rapidly rotating stars have revealed the presence of regular patterns in their pulsation spectra. This has raised the question as to their physical origin, and in particular, whether they can be explained by an…

Solar and Stellar Astrophysics · Physics 2015-06-17 Daniel R. Reese , Francisco Espinosa Lara , Michel Rieutord

Asteroseismic inferences of main-sequence solar-like oscillators often rely on best-fit models. However, these models cannot fully reproduce the observed mode frequencies, suggesting that the internal structure of the model does not fully…

Solar and Stellar Astrophysics · Physics 2025-07-08 Lynn Buchele , Earl P. Bellinger , Saskia Hekker , Sarbani Basu

We use I band imaging to perform a variability survey of the 13 Myr-old cluster h Per. We find a significant fraction of the cluster members to be variable. Most importantly, we find that variable members lie almost entirely on the…

Solar and Stellar Astrophysics · Physics 2015-05-13 Eric S. Saunders , Tim Naylor , Nathan Mayne , S. P. Littlefair

Context. In asteroseismology the pulsation mode frequencies of a star are the fundamental data that are compared to theoretical predictions to determine a star's interior physics. Recent significant advances in the numerical, theoretical…

Solar and Stellar Astrophysics · Physics 2021-12-22 Dominic M. Bowman , Mathias Michielsen

It has been shown that there is a potential ambiguity in the asteroseismic determination of the location of internal structures in a pulsating star. We show how, in the case of high-order non-radial acoustic modes, it is possible to remove…

Astrophysics · Physics 2009-11-10 Andrea Miglio , Elio Antonello

The theoretical oscillation frequencies of even the best asteroseismic models of solar-like oscillators show significant differences from observed oscillation frequencies. Structure inversions seek to use these frequency differences to…

Solar and Stellar Astrophysics · Physics 2024-02-02 Lynn Buchele , Earl P. Bellinger , Saskia Hekker , Sarbani Basu , Warrick Ball , Jørgen 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

Recent asteroseismic observations by the $\it Kepler$ space mission have revealed the dip fine structure in the period-spacing versus period diagram of rapidly rotating $\gamma$ Doradus stars. Following the successful reproduction of the…

Solar and Stellar Astrophysics · Physics 2022-06-28 Takato Tokuno , Masao Takata

The frequency ratios and of HD 49933 exhibit an increase at high frequencies. This behavior also exists in the ratios of other stars, which is considered to result from the low signal-to-noise ratio and the larger line width at the…

Solar and Stellar Astrophysics · Physics 2015-06-18 Zhie Liu , Wuming Yang , Shaolan Bi , Zhijia Tian , Kang Liu , Zhishuai Ge , Jie Yu , Tanda Li , Xiaoyan Tan , Xin He , Yaqian Wu , P. Chintarungruangchai

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

Spectroscopic studies of Galactic O and B stars show that many stars with masses above 8 M$_{\odot}$ are observed in the HR diagram just beyond the Main-Sequence (MS) band predicted by stellar models computed with a moderate overshooting.…

Context. Convective regions in stellar models are always associated with uncertainties, for example due to extra-mixing or the possible inaccurate position of the transition from convective to radiative transport of energy. These have a…

Solar and Stellar Astrophysics · Physics 2018-02-07 G. Buldgen , D. R. Reese , M. A. Dupret