Results 21 to 30 of about 1,022 (263)
Techniques for observing stellar oscillations [PDF]
Symposium - International Astronomical Union, 1988 Although stellar oscillations have been observed for more than two centuries, the demands of asteroseismology require new observations of substantially higher precision. Two major techniques are reviewed: Doppler spectroscopy and photometry. Fundamental limitations are described using the sun as a representative stellar target. The current state of the
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Chaotic Dynamics of Stellar Spin in Binaries and the Production of Misaligned Hot Jupiters
EPJ Web of Conferences, 2015 Motivated by observed hot Jupiter systems with high stellar obliquities, we examine the dynamics of stellar spin in planetary systems with distant stellar companions, with inclinations sufficiently high so that the planet undergoes Kozai-Lidov ...
Anderson Kassandra R. +2 more
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Kolmogorov Unstable Stellar Oscillations [PDF]
Solar Physics, 1983 AbstractWe survey the mathematics of non-linear Hamiltonian oscillations with emphasis being laid on the more recently discovered Kolmogorov instability. In the context of radial adiabatic oscillations of stars this formalism predicts a Kolmogorov instability even at low oscillation energies, provided that sufficiently high linear asymptotic modes have
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Stellar oscillations in modified gravity [PDF]
Physical Review D, 2013 Starting from the equations of modified gravity hydrodynamics, we derive the equ tions of motion governing linear, adiabatic, radial perturbations of stars in scalar-tensor theories. There are two new features: first, the eigenvalue equation for the period of stellar oscillations is modified such that the eigenfrequencies are always larger than ...
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Latitudinal Propagation of Thermal Rossby Waves in Stellar Convection Zones
The Astrophysical Journal, 2023 Using an analytic model, we derive the eigenfrequencies for thermal Rossby waves that are trapped radially and latitudinally in an isentropically stratified atmosphere. We ignore the star’s curvature and work in an equatorial f-plane geometry.
Rekha Jain, Bradley W. Hindman
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Asteroseismic modelling of the Binary HD 176465
EPJ Web of Conferences, 2017 The detection and analysis of oscillations in binary star systems is critical in understanding stellar structure and evolution. This is partly because such systems have the same initial chemical composition and age.
Nsamba B. +6 more
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Stellar oscillations - I - The adiabatic case [PDF]
EAS Publications Series, 2015 This lecture on adiabatic oscillations is intended to present the basis of asteroseismology and to serve as an introduction for other lectures of the EES 2014. It also exposes the state-of-the-art of solar-like oscillation analysis, as revealed by the space missions CoRoT and Kepler.
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Detection of stellar oscillations in HWVir
Open Astronomy, 2016 We present our analysis of K2 observations of the binary system, HWVir. We processed the raw Kepler data and used Fourier analysis to search for periodic signals that could be associated with pulsations.
Baran Andrzej S. +2 more
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Dark matter induced stellar oscillations
Monthly Notices of the Royal Astronomical Society: Letters, 2023 ABSTRACT It has been hypothesized that dark matter is comprised of ultra-light bosons whose collective phenomena can be described as a scalar field undergoing coherent oscillations. Examples include axion and fuzzy dark matter models. In this ultra-light dark matter (ULDM) scenario, the harmonic variation in the field’s energy–momentum ...
Sakstein, J., Saltas, Ippocratis D.
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Vertical oscillations of fluid and stellar discs [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 A satellite galaxy or dark matter subhalo that passes through a stellar disk may excite coherent oscillations in the disk perpendicular to its plane. We determine the properties of these modes for various self-gravitating plane symmetric systems (Spitzer sheets) using the matrix method of Kalnajs.
Widrow, Lawrence M., Bonner, Gage
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