English
Related papers

Related papers: Satellite observations reveal shorter periodic inn…

200 papers

The presence of dips in the gravito-inertial modes period-spacing pattern of gamma-Dor stars is now well established by recent asteroseismic studies. Such Lorentzian-shaped inertial dips arise from the interaction of gravito-inertial modes…

Solar and Stellar Astrophysics · Physics 2024-10-30 Lucas Barrault , Stéphane Mathis , Lisa Bugnet

Two main seismic features characterize the Earth's inner core: a North-South polar anisotropy and an East-West asymmetry of P-wave velocity and attenuation. Anisotropy is expected if shear deformation is induced by convective motions.…

Geophysics · Physics 2015-06-04 Hugau Mizzon , Marc Monnereau

It has been shown that a discontinuity in the derivatives of the sound speed at the edge of the convective regions inside a star gives rise to a characteristic oscillatory signal in the frequencies of stellar oscillations. This oscillatory…

Astrophysics · Physics 2009-11-07 Anwesh Mazumdar , H. M. Antia

While the main causes of the temporal gravity variations observed by the GRACE space mission result from water mass redistributions occurring at the surface of the Earth in response to climatic and anthropogenic forcings (e.g., changes in…

Geophysics · Physics 2020-12-22 Mioara Mandea , Véronique Dehant , Anny Cazenave

In nominal mission scenarios, geostationary satellites perform end-of-life orbit maneuvers to reach suitable disposal orbits, where they do not interfere with operational satellites. This research investigates the long-term orbit evolution…

Earth and Planetary Astrophysics · Physics 2021-04-06 Simone Proietti , Roberto Flores , Elena Fantino , Mauro Pontani

The energy balance in the corona of the Sun is the key to the long-standing coronal heating dilemma, which could be potentially revealed by observational studies of decayless kink oscillations of coronal plasma loops. A bundle of very long…

Solar and Stellar Astrophysics · Physics 2023-08-11 Sihui Zhong , Valery M. Nakariakov , Yuhu Miao , Libo Fu , Ding Yuan

Flow vorticity is a fundamental property of turbulent convection in rotating systems. Solar supergranules exhibit a preferred sense of rotation, which depends on the hemisphere. This is due to the Coriolis force acting on the diverging…

Solar and Stellar Astrophysics · Physics 2015-09-09 J. Langfellner , L. Gizon , A. C. Birch

Coronal loop oscillations are common phenomena in the solar corona, which are often classified as decaying and decayless oscillations. Using the high-resolution observation measured by the Extreme Ultraviolet Imager (EUI) onboard the Solar…

Solar and Stellar Astrophysics · Physics 2023-02-15 Dong Li , David M. Long

We study prospects for seismic sounding the layer of a partial mixing above the convective core in main-sequence stars with masses in the 1.2 -- 1.9 solar mass range. There is an initial tendency to an increase of convective core mass in…

Astrophysics · Physics 2007-05-23 B. L. Popielski , W. A. Dziembowski

Hydrogeodesy can benefit greatly from the use of Global Positioning System (GPS) displacements to analyse local changes in the hydrosphere, which the commonly used Gravity Recovery and Climate Experiment (GRACE) mission is unable to provide…

Geophysics · Physics 2024-01-18 Gael Kermarrec , Anna Klos , Artur Lenczuk , Janusz Bogusz

Context. Gamma Doradus (hereafter $\gamma$~Dor) stars are gravity-mode pulsators whose periods carry information about the internal structure of the star. These periods are especially sensitive to the internal rotation and chemical mixing,…

Solar and Stellar Astrophysics · Physics 2022-12-21 Stefano Garcia , Timothy Van Reeth , Joris De Ridder , Conny Aerts

In a recent article by Dickey, J. O., Marcus, S.L. and O. de Viron, 2011, the authors show evidences for correlations in the multi-decadal variability of Earth's rotation rate [i.e., length of day (LOD)], the angular momentum of the core…

Data Analysis, Statistics and Probability · Physics 2011-03-28 Stefano Sello

Context : We still do not know which mechanisms are responsible for the transport of angular momentum inside stars. The recent detection of mixed modes that contain the signature of rotation in the spectra of Kepler subgiants and red giants…

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

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Based on the Irkutsk fast monostatic chirp ionosonde data we made a statistical analysis of ionospheric effects for 28 earthquakes which appeared in 2011-2016 years. These effects are related with surface (Rayleigh) seismic waves far from…

The obliquity of the Earth, which controls our seasons, varies by only ~2.5 degrees over ~40,000 years, and its eccentricity varies by only ~0.05 over 100,000 years. Nonetheless, these small variations influence Earth's ice ages. For…

Earth and Planetary Astrophysics · Physics 2018-01-31 Russell Deitrick , Rory Barnes , Thomas R. Quinn , John Armstrong , Benjamin Charnay , Caitlyn Wilhelm

The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode…

General Relativity and Quantum Cosmology · Physics 2014-09-05 Michael Coughlin , Jan Harms

Aims: We aim at characterizing the inward transition from convective to radiative energy transport at the base of the convective envelope of the solar-like oscillator HD 52265 recently observed by the CoRoT satellite. Methods: We…

Solar and Stellar Astrophysics · Physics 2015-06-05 Yveline Lebreton , MarieJo Goupil

Herein we show that the historical records of mid-latitude auroras from 1700 to 1966 present oscillations with periods of about 9, 10-11, 20-21, 30 and 60 years. The same frequencies are found in proxy and instrumental global surface…

Earth and Planetary Astrophysics · Physics 2015-03-20 Nicola Scafetta