Results 41 to 50 of about 958,871 (209)

How Are the Abnormally Hot Chromosphere and Corona Heated by the Solar Magnetic Fields?

The Astrophysical Journal
The corona is a structure possessed by stars, including the Sun. The abnormal heating of the solar corona and chromosphere is one of the greatest mysteries in modern astronomy.
K. J. Li, J. C. Xu, W. Feng, J. L. Xie, X. J. Shi, L. H. Deng   +5 more
doaj   +1 more source

THE FORMATION OF THE Hα LINE IN THE SOLAR CHROMOSPHERE [PDF]

The Astrophysical Journal, 2012
We use state-of-the-art radiation-MHD simulations and 3D non-LTE radiative transfer computations to investigate \Halpha\ line formation in the solar chromosphere and apply the results of this investigation to develop the potential of \Halpha\ as diagnostic of the chromosphere.
J. Leenaarts, M. Carlsson, L. Rouppe van der Voort   +2 more
openaire   +2 more sources

Parker Solar Probe Observations of Proton Core‐Beam Distributions in Heliospheric Current Sheet Region: Quasilinear Instability Analysis Combined With Collisional Relaxation

Journal of Geophysical Research: Space Physics, Volume 131, Issue 4, April 2026.
Abstract Parker Solar Probe has been proven as instrumental for the observation of young solar wind. During the encounters E‐07 and E‐08, PSP recorded the core plus beaming protons crossing the heliospheric current Sheet region. When the observed PSP data is plotted in the temperature ratio versus parallel beta space, it is found that the occurrence ...
M. Rashid, P. H. Yoon, J. Huang, C. Salem, M. Sarfraz, S. Alnussirat, R. A. López, J. Seough, H. Xie, D. Larson, R. Livi   +10 more
wiley   +1 more source

Numerical Experiment on the Influence of Granulation-induced Waves on Solar Chromosphere Heating and Plasma Outflows in a Magnetic Arcade

The Astrophysical Journal
This paper offers a fresh perspective on solar chromosphere heating and plasma outflows, focusing on the contribution of waves generated by solar granulation.
M. Kumar, K. Murawski, B. Kuźma, E. K. J. Kilpua, S. Poedts, R. Erdélyi   +5 more
doaj   +1 more source

Alfvén wave dissipation in the solar chromosphere [PDF]

Nature Physics, 2018
Magneto-hydrodynamic (MHD) Alfvén waves have been a focus of laboratory plasma physics and astrophysics for over half a century. Their unique nature makes them ideal energy transporters, and while the solar atmosphere provides preferential conditions for their existence, direct detection has proved difficult as a result of their evolving and dynamic ...
Samuel D. T. Grant, David B. Jess, Teimuraz V. Zaqarashvili, Christian Beck, Hector Socas-Navarro, Markus J. Aschwanden, Peter H. Keys, Damian J. Christian, Scott J. Houston, Rebecca L. Hewitt   +9 more
openaire   +4 more sources

Solar mean magnetic field of the chromosphere

Journal of Astrophysics and Astronomy, 2023
The Solar Mean Magnetic Field (SMMF) is the mean value of the line of sight (LOS) component of the solar vector magnetic field averaged over the visible hemisphere of the Sun. So far, the studies on SMMF have mostly been confined to the magnetic field measurements at the photosphere. In this study, we calculate and analyse the SMMF using magnetic field
M. Vishnu, K. Nagaraju, Harsh Mathur
openaire   +2 more sources

Reconstruction of Two‐Dimensional Magnetohydrodynamic and Hall Magnetohydrodynamic Equilibria in Space Using Physics‐Informed Neural Networks

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 2, April 2026.
Abstract We present a novel data analysis technique based on physics‐informed neural networks (PINNs) to reconstruct two‐dimensional (2D) magnetohydrodynamic (MHD) and Hall MHD equilibria in a space plasma from in situ spacecraft measurements. Our method incorporates the steady‐state MHD or Hall MHD equations—a set of partial differential equations ...
Hiroshi Hasegawa, Eunjin Choi, Kyoung‐Joo Hwang, Kyunghwan Dokgo   +3 more
wiley   +1 more source

Reconstructing Historical Solar Indices for Predicting Past Space Weather Events

Space Weather, Volume 24, Issue 4, April 2026.
Abstract Modeling and forecasting the near‐Earth space environment, specifically the thermosphere, is particularly important because it affects the motion of low‐Earth orbit objects through atmospheric drag. Solar indices such as F10.7, S10.7, M10.7, and Y10.7 are commonly used as inputs to ionospheric and thermospheric density models.
Poshan Belbase, Denny M. Oliveira, Theodosios Chatzistergos, Gangkai Poh, Eftyhia Zesta   +4 more
wiley   +1 more source

Collisional dissipation of Alfvén waves in a partially ionised solar chromosphere [PDF]

, 2005
Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised. The lower chromosphere contains neutral atoms, the existence of which greatly increases the efficiency of the damping of waves due to collisional ...
J. E. Leake, T. D. Arber, Leake, J. E. (James E.), Khodachenko, M. L., Arber, T. D., M. L. Khodachenko   +5 more
core   +1 more source

Searching for Rotational X‐Ray Modulation on TIC 277539431

Astronomische Nachrichten, Volume 347, Issue 3, March 2026.
ABSTRACT TIC 277539431, a fast rotating M7 dwarf, was detected to host the highest latitude flare to date at 81°$$ {81}^{{}^{\circ}} $$. Magnetic activity like stellar flares occurring at high latitude indicate occurrence of coronal loops at these latitudes on fully‐convective M dwarfs. In contrast, sunspots usually occur below 30°$$ {30}^{{}^{\circ}} $
Desmond Dsouza, Katja Poppenhäger, Ekaterina Ilin   +2 more
wiley   +1 more source