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Related papers: The RR Lyrae U Com as a test for nonlinear pulsati…

200 papers

We present a radial velocity analysis of 20 solar neighborhood RR Lyrae and 3 Population II Cepheids variables. We obtained high-resolution, moderate-to-high signal-to-noise ratio spectra for most stars and obtained spectra were covering…

Solar and Stellar Astrophysics · Physics 2017-11-16 N. E. Britavskiy , E. Pancino , V. Tsymbal , D. Romano , L. Fossati

We consider both mode calculations and time evolutions of axial r-modes for relativistic uniformly rotating non-barotropic neutron stars, using the slow-rotation formalism, in which rotational corrections are considered up to linear order…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Johannes Ruoff , Kostas D. Kokkotas

White-light stellar flares are now reported by the thousands in long-baseline, high precision, broad-band photometry from missions like Kepler, K2, and TESS. These observations are crucial inputs for assessments of biosignatures in…

Solar and Stellar Astrophysics · Physics 2022-11-01 Adam F. Kowalski

Recent work has shown that differential rotation, producing large scale drifts of fluid elements along stellar latitudes, is an unavoidable feature of r-modes in the nonlinear theory. We investigate the role of this differential rotation in…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Paulo M. Sá , Brigitte Tomé

We update the capabilities of the open-knowledge software instrument Modules for Experiments in Stellar Astrophysics (MESA). RSP is a new functionality in MESAstar that models the non-linear radial stellar pulsations that characterize RR…

The analysis of recent, extended multicolour CCD and archive photoelectric, photographic and visual observations has revealed several important properties of RZ Lyr, an RRab-type variable exhibiting large-amplitude Blazhko modulation. On…

The contour method is a new approach to calculating the non-adiabatic pulsation frequencies of stars. These frequencies can be found by solving for the complex roots of a characteristic equation constructed from the linear non-adiabatic…

Solar and Stellar Astrophysics · Physics 2020-08-26 J. Goldstein , R. H. D. Townsend

We study time evolutions of superfluid neutron stars, focussing on the nature of the oscillation spectrum, the effect of mutual friction force on the oscillations and the hydrodynamical spin-up phase of pulsar glitches. We linearise the…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Passamonti , N. Andersson

Accurate and reliable gravitational waveform models are crucial in determining the properties of compact binary mergers. In particular, next-generation gravitational-wave detectors will require more accurate waveforms to avoid biases in the…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Adrian Abac , Felip A. Ramis Vidal , Marta Colleoni , Anna Puecher , Alejandra Gonzalez , Tim Dietrich

Automatic classification methods applied to sky surveys have revolutionized the astronomical target selection process. Most surveys generate a vast amount of time series, or \quotes{lightcurves}, that represent the brightness variability of…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Nicolas Castro , Pavlos Protopapas , Karim Pichara

We study non-linear axisymmetric pulsations of rotating relativistic stars using a general relativistic hydrodynamics code under the assumption of a conformal flatness. We compare our results to previous simulations where the spacetime…

Astrophysics · Physics 2009-11-11 Harald Dimmelmeier , Nikolaos Stergioulas , Jose A. Font

Observations suggest that in normal period radio pulsars, coherent curvature radiation is excited within 10$\%$ of the light cylinder. The coherence is attributed to Langmuir mode instability in a relativistically streaming one-dimensional…

High Energy Astrophysical Phenomena · Physics 2022-08-15 Sk. Minhajur Rahaman , Dipanjan Mitra , George I. Melikidze

The prevalence of binary stars at close separations implies that many of these systems will interact or merge during the binary's lifetime. This paper presents hydrodynamic simulations of the scenario of binary coalescence through unstable…

Solar and Stellar Astrophysics · Physics 2019-05-29 Morgan MacLeod , Michelle Vick , Dong Lai , James M. Stone

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different…

Solar and Stellar Astrophysics · Physics 2016-01-18 Günter Houdek , Marc-Antoine Dupret

Convection plays an essential role in the emerging intensity for many stars that will be observed by Gaia. Convective-related surface structures affect the shape, shift, and asymmetry of absorption lines, the phocentric and photometric…

Solar and Stellar Astrophysics · Physics 2011-12-13 A. Chiavassa , L. Bigot , F. Thevenin , R. Collet , G. Jasniewicz , Z. Magic , M. Asplund

A program is outlined, and first results described, in which fully three-dimensional, time dependent simulations of hydrodynamic turbulence are used as a basis for theoretical investigation of the physics of turbulence in stars. The…

Solar and Stellar Astrophysics · Physics 2015-05-14 W. David Arnett , Casey Meakin

Developments of this far-reaching research field are summarized from an observational point of view, mentioning important and interesting phenomena discovered recently by photometry of stellar oscillations of any kind. A special emphasis is…

Solar and Stellar Astrophysics · Physics 2014-04-08 L. Szabados

CONTEXT: Spectral-line asymmetries and wavelength shifts are signatures of hydrodynamics in solar and stellar atmospheres. Theory may precisely predict idealized lines, but observed spectra are limited by blends, too few suitable lines,…

Astrophysics · Physics 2009-11-13 Dainis Dravins

We investigate the potential of multi-colour photometry for partial mode identification in both long- and short-period variable subdwarf B stars. The technique presented is based on the fact that the frequency dependence of an oscillation's…

Astrophysics · Physics 2009-11-11 S. K. Randall , G. Fontaine , P. Brassard , P. Bergeron

We present a robust approach to incorporating models for the time-variable broadening of the pulse profile due to scattering in the ionized interstellar medium into profile-domain pulsar timing analysis. We use this approach to…

Instrumentation and Methods for Astrophysics · Physics 2017-04-12 L. Lentati , M. Kerr , S. Dai , R. M. Shannon , G. Hobbs , S. Oslowski