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On the main sequence, the asteroseismic small frequency separation $\delta\nu_{02}$ between radial and quadrupole p-modes is customarily interpreted to be a direct diagnostic of internal structure. Such an interpretation is based on a…

Solar and Stellar Astrophysics · Physics 2025-01-10 J. M. Joel Ong , Christopher J. Lindsay , Claudia Reyes , Dennis Stello , Ian W. Roxburgh

Astronomy is in an era where all-sky surveys are mapping the Galaxy. The plethora of photometric, spectroscopic, asteroseismic and astrometric data allows us to characterise the comprising stars in detail. Here we quantify to what extent…

Solar and Stellar Astrophysics · Physics 2017-05-03 George C. Angelou , Earl P. Bellinger , Saskia Hekker , Sarbani Basu

The length of the asteroseismic timeseries obtained from the Kepler satellite analysed here span 19 months. Kepler provides the longest continuous timeseries currently available, which calls for a study of the influence of the increased…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. Hekker , Y. Elsworth , B. Mosser , T. Kallinger , W. J. Chaplin , J. De Ridder , R. A. Garcia , D. Stello , B. D. Clarke , J. R. Hall , K. A. Ibrahim

It is thought that magnetic fields must be present in the interiors of stars to resolve certain discrepancies between theory and observation (e.g. angular momentum transport), but such fields are difficult to detect and characterise.…

Solar and Stellar Astrophysics · Physics 2021-04-21 Shyeh Tjing Loi

Determining the mass of stars is crucial both to improving stellar evolution theory and to characterising exoplanetary systems. Asteroseismology offers a promising way to estimate stellar mean density. When combined with accurate radii…

Solar and Stellar Astrophysics · Physics 2015-06-03 D. R. Reese , J. P. Marques , M. J. Goupil , M. J. Thompson , S. Deheuvels

An increasingly popular method to determine stellar ages of red-giant stars for the purpose of Galactic archaeology is asteroseismic grid-based modelling (GBM). In asteroseismic GBM of red-giant stars with solar-like oscillations the large…

Solar and Stellar Astrophysics · Physics 2019-11-01 Saskia Hekker , Sarbani Basu

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

Asteroseismic parameters allow us to measure the basic stellar properties of field giants observed far across the Galaxy. Most of such determinations are, up to now, based on simple scaling relations involving the large frequency…

We develop a novel method based on machine learning principles to achieve optimal initiation of CPU-intensive computations for forward asteroseismic modeling in a multi-D parameter space. A deep neural network is trained on a precomputed…

Solar and Stellar Astrophysics · Physics 2019-08-29 Luc Hendriks , Conny Aerts

Accurate and precise values of radii and masses of stars are needed to correctly estimate properties of extrasolar planets. We examine the effect of uncertainties in stellar model parameters on estimates of the masses, radii and average…

Solar and Stellar Astrophysics · Physics 2015-06-03 Sarbani Basu , Graham A. Verner , William J. Chaplin , Yvonne Elsworth

Pulsational properties of 1.8 M$_{\odot}$ stellar models covering the latest stages of contraction toward the main sequence up to early hydrogen burning phases are investigated by means of linear nonadiabatic analyses. Results confirm that…

Astrophysics · Physics 2009-11-06 Marian Suran , MarieJo Goupil , Annie Baglin , Yveline Lebreton , Claude Catala

We assess the potential of asteroseismology for determining the fundamental properties of individual $\delta$ Scuti stars. We computed a grid of evolution and adiabatic pulsation models using the Yale Rotating Evolution Code to study the…

Astrophysics · Physics 2009-11-07 M. R. Templeton , S. Basu , P. Demarque

The large separations between the oscillation frequencies of solar-like stars are measures of stellar mean density. The separations have been thought to be mostly constant in the observed range of frequencies. However, detailed…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Yıldız , Z. Çelik Orhan , C. Kayhan

Stars are not perfectly spherically symmetric. They are deformed by rotation and magnetic fields. Until now, the study of stellar shapes has only been possible with optical interferometry for a few of the fastest-rotating nearby stars. We…

The influence of rotational mixing on the evolution and asteroseismic properties of solar-type stars is studied. Rotational mixing changes the global properties of a solar-type star with a significant increase of the effective temperature…

Solar and Stellar Astrophysics · Physics 2015-05-20 P. Eggenberger , G. Meynet , A. Maeder , A. Miglio , J. Montalban , F. Carrier , S. Mathis , C. Charbonnel , S. Talon

Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time…

Instrumentation and Methods for Astrophysics · Physics 2015-05-12 Chao Liu , Min Fang , Yue Wu , Li-Cai Deng , Liang Wang , Wei Wang , Jian-Ning Fu , Yong-Hui Hou , Guang-Wei Li , Yong Zhang

Intermediate degree modes of the solar oscillations have previously been used to determine the solar helium abundance to a high degree of precision. However, we cannot expect to observe such modes in other stars. In this work we investigate…

Astrophysics · Physics 2009-11-10 Sarbani Basu , Anwesh Mazumdar , H. M Antia , Pierre Demarque

Context: Mode identification has remained a major obstacle in the interpretation of pulsation spectra in rapidly rotating stars. Aims: We would like to test mode identification methods and seismic diagnostics in rapidly rotating stars,…

Solar and Stellar Astrophysics · Physics 2017-05-24 D. R. Reese , F. Lignières , J. Ballot , M. -A. Dupret , C. Barban , C. van 't Veer-Menneret , K. B. MacGregor

Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-studied cluster such as the Hyades, the masses of the red…

The measurements of pressure-mode and mixed-mode oscillation frequencies in subgiant stars offer a unique opportunity to probe their internal structures -- from the surface to the deep interior -- and to precisely determine their global…