Results 51 to 60 of about 1,537 (202)

A Review of Space Helioseismology [PDF]

Symposium - International Astronomical Union, 1997
The helioseismology started in 1960 with the discovery of oscillations of the velocity field on the solar surface by Leighton, 1960. The mechanism producing these oscillations remained unexplained for the next ten years until Ulrich, 1970, and independently Leibacher and Stein, 1971, demonstrated that acoustic waves trapped beneath the solar surface ...
openaire   +1 more source

Helioseismology, solar models and solar neutrinos

, 1999
We review recent advances concerning helioseismology, solar models and solar neutrinos. Particularly we shall address the following points: i) helioseismic tests of recent SSMs; ii)the accuracy of the helioseismic determination of the sound speed near ...
Fiorentini G., Ricci B., FIORENTINI, Giovanni, RICCI, Barbara   +3 more
core   +1 more source

Recent Developments in Degenerate Higher Order Scalar Tensor Theories

Annalen der Physik, Volume 537, Issue 2, February 2025.
Degenerate Higher Order Scalar Tensor theories are reviewed, together with their applications in cosmology and astrophysics. These theories have been applied to build models of the early universe, in the description of the late‐time cosmic acceleration, as well as in astrophysics, including black hole physics. They have the potential to provide answers
Andrei Lazanu
wiley   +1 more source

Nonzero Phase Shifts of Acoustic Waves in the Lower Solar Atmosphere Measured from Realistic Simulations and Their Role in Local Helioseismology

The Astrophysical Journal, 2023
Previous studies analyzing the evanescent nature of acoustic waves in the lower solar atmosphere, up to 300 km above the photosphere, have shown an unexpected phase shift of an order of 1 s between different heights.
M. Waidele, Junwei Zhao, I. N. Kitiashvili   +2 more
doaj   +1 more source

Extreme Space Weather Events of the Past 30 Years: Preparation for Data From Mission Vigil

Earth and Space Science, Volume 12, Issue 2, February 2025.
Abstract Extreme Space Weather events can negatively affect ground‐based infrastructure and satellite communications. European Space Agency plans to launch a new operational mission, Vigil, to monitor space weather activity and provide timely warnings about immediate danger.
Adam Majirský, Šimon Mackovjak, Silvia Kostárová, Samuel Amrich   +3 more
wiley   +1 more source

Assessment of DKIST/VTF capabilities for the detection of local acoustic source wavefronts

Frontiers in Astronomy and Space Sciences
IntroductionRecent studies have demonstrated that temporal filtering can successfully identify local acoustic source wavefronts in radiative magnetohydrodynamic simulations of the solar photosphere.
Corinne Morrell, Corinne Morrell, Mark P. Rast, Mark P. Rast, Shah Mohammad Bahauddin, Shah Mohammad Bahauddin, Ivan Milić   +6 more
doaj   +1 more source

Direct assessment of SDO/HMI helioseismology of active regions on the Sun’s far side using SO/PHI magnetograms

Astronomy & Astrophysics, 2023
Context. Earth-side observations of solar p modes can be used to image and monitor magnetic activity on the Sun’s far side. In this work, we use magnetograms of the far side obtained by the Polarimetric and Helioseismic Imager (PHI) on board Solar ...
Yang D., Gizon L., Barucq H., Hirzberger J., Orozco Suárez D., Albert K., Albelo Jorge N., Appourchaux T., Alvarez-Herrero A., Blanco Rodríguez J., Gandorfer A., Germerott D., Guerrero L., Gutierrez-Marques P., Kahil F., Kolleck M., Solanki S. K., del Toro Iniesta J. C., Volkmer R., Woch J., Pérez-Grande I., Sanchis Kilders E., Balaguer Jiménez M., Bellot Rubio L. R., Calchetti D., Carmona M., Deutsch W., Feller A., Fernandez-Rico G., Fernández-Medina A., García Parejo P., Gasent Blesa J. L., Grauf B., Heerlein K., Korpi-Lagg A., Lange T., López Jiménez A., Maue T., Meller R., Moreno Vacas A., Müller R., Nakai E., Schmidt W., Schou J., Schühle U., Sinjan J., Staub J., Strecker H., Torralbo I., Valori G.   +49 more
doaj   +1 more source

Estimation of Spectral Solar Irradiance in the Ecliptic Plane Using Synthetic Solar Surface Magnetograms

Journal of Geophysical Research: Space Physics, Volume 129, Issue 5, May 2024.
Abstract The primary external energy input to planetary atmospheres comes from solar radiation. Accurate estimates of solar irradiance are needed in order to understand atmospheric conditions at other planets. Many studies have interpolated Earth‐based irradiance measurements at other planets, disregarding the evolution of solar features, which are ...
I. de Oliveira, K. Sowmya, N.‐E. Nèmec, A. I. Shapiro   +3 more
wiley   +1 more source

Global helioseismology (WP4.1): From the Sun to the stars & solar analogs

EPJ Web of Conferences, 2017
Sun-as-a star observations put our star as a reference for stellar observations. Here, I review the activities in which the SPACEINN global seismology team (Working Package WP4.1) has worked during the past 3 years. In particular, we will explain the new
García Rafael A.
doaj   +1 more source

Observational Evidence of Shallow Origins for the Magnetic Fields of Solar Cycles

Frontiers in Astronomy and Space Sciences, 2018
Observational evidence for the origin of active region magnetic fields has been sought from published information on extended solar cycles, statistical distributions of active regions and ephemeral regions, helioseismology results, positional ...
Sara F. Martin
doaj   +1 more source