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Related papers: Coronal bright point statistics I. Lifetime, shape…

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A recent analysis has suggested that the heating of plasma loops in the solar corona depends not just on the Poynting flux but also on processes yet to be identified. This discovery reflects and refines earlier questions such as, why and…

Solar and Stellar Astrophysics · Physics 2024-08-16 P. G. Judge , N. P. M. Kuin

We aim to reproduce the structure of the corona above a solar active region as seen in the extreme ultraviolet (EUV) using a three-dimensional magnetohydrodynamic (3D MHD) model. The 3D MHD data-driven model solves the induction equation…

Solar and Stellar Astrophysics · Physics 2019-04-30 Jörn Warnecke , Hardi Peter

Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…

Solar and Stellar Astrophysics · Physics 2024-11-20 L. P. Chitta , M. van Noort , H. N. Smitha , E. R. Priest , L. H. M. Rouppe van der Voort

The solar atmosphere may be heated by Alfven waves that propagate up from the convection zone and dissipate their energy in the chromosphere and corona. To further test this theory, we consider wave heating in an active region observed on…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. Asgari-Targhi , A. A. van Ballegooijen , S. R. Cranmer , E. E. DeLuca

Data obtained in the framework of the INTERBALL-Tail Probe (1995-2000) and RHESSI (from 2002 to the present) projects have revealed variations in the X-ray intensity of the solar corona in the photon energy range of 2-15 keV during the…

High Energy Astrophysical Phenomena · Physics 2019-04-08 I. K. Mirzoeva , S. G. Chefranov

We use the first publically available data from the Daniel K. Inouye Solar Telescope (DKIST) to track magnetic connections from the solar photosphere into the corona. We scrutinize relationships between chromospheric magnetism and bright…

Solar and Stellar Astrophysics · Physics 2023-11-03 Philip Judge , Lucia Kleint , Roberto Casini , Alfred de Wijn , Tom Schad , Alexandra Tritschler

Many studies of the solar corona have shown that the observed X-ray luminosity is well correlated with the total unsigned magnetic flux. In this paper we present results from the extensive numerical modeling of active regions observed with…

Astrophysics · Physics 2016-08-30 Harry P. Warren , Amy R. Winebarger

The chromosphere is a complex region that acts as an intermediary between the magnetic flux emergence in the photosphere and the magnetic features seen in the corona. Large eruptions in the chromosphere of flares and filaments are often…

Solar and Stellar Astrophysics · Physics 2017-09-20 Michael S. Kirk , K. S. Balasubramaniam , Jason Jackiewicz , Holly R. Gilbert

The quiescent or dynamic nature of fine scale ray-like features in the sun corona, observed in visible light, is still an open question. Here, we show that most of daily and hourly periodic variations in visible light brightness of the high…

Solar and Stellar Astrophysics · Physics 2025-09-16 Nathalia Alzate , Simone Di Matteo

We report observations of bright dots (BDs) in a sunspot penumbra using High Resolution Coronal Imager (Hi-C) data in 193 \AA\ and examine their sizes, lifetimes, speeds, and intensities. The sizes of the BDs are on the order of 1\arcsec\…

Solar and Stellar Astrophysics · Physics 2016-05-25 Shane E. Alpert , Sanjiv K. Tiwari , Ronald L. Moore , Amy R. Winebarger , Sabrina L. Savage

This paper is a follow up of the article where Lemaire and Stegen (2016) introduced their DYN method to calculate coronal temperature profiles from given radial distributions of the coronal and solar wind (SW) electron densities. Several…

Solar and Stellar Astrophysics · Physics 2021-04-21 Joseph F. Lemaire , Athanassios C. Katsiyannis

The plasma parameters such as the electron density and temperature plays a key role in the dynamics of the solar atmosphere. These characteristics are important in solar physics, because they can help to understand the physics in the solar…

Solar and Stellar Astrophysics · Physics 2018-04-12 J. M Rodríguez Gómez , L. Vieira , A. Dal Lago , J. Palacios

The temperature of the solar atmosphere increases from thousands to millions of degrees moving from the lower layer (chromosphere) to the outermost one (corona), while the density drops accordingly. The mechanism behind this phenomenon,…

Solar and Stellar Astrophysics · Physics 2023-12-27 Luca Barbieri , Lapo Casetti , Andrea Verdini , Simone Landi

We present coordinated coronal observations of the August 21, 2017 total solar eclipse with the Airborne Infrared Spectrometer (AIR-Spec) and the Extreme-ultraviolet Imaging Spectrometer (EIS). These instruments provide an unprecedented…

Solar and Stellar Astrophysics · Physics 2019-08-07 Chad A. Madsen , Jenna E. Samra , Giulio Del Zanna , Edward E. DeLuca

Coronae exist in most astrophysical objects: stars, accretion disks, and individual galaxies and clusters of galaxies. Coronae in these varied systems have some common properties: 1) hydrostatic equilibrium in background gravity is a good…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-10 Prateek Sharma

The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and coronal holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas a strong…

Solar and Stellar Astrophysics · Physics 2015-06-11 B. N. Dwivedi , K. Wilhelm

The problem of solar corona heating remains one of key puzzles in astrophysics for a few decades; but none of the proposed mechanisms can give a definitive answer to this question. As a result, the novel scenarios are still suggested. Here,…

Solar and Stellar Astrophysics · Physics 2020-05-15 Yurii V. Dumin

Small scale extreme ultraviolet (EUV) transient brightenings are observationally abundant and critically important to investigate. Determining whether they share the same physical mechanisms as larger scale flares would have significant…

The Sun's corona has interested researchers for multiple reasons, including the search for solution for the famous coronal heating problem and a purely practical consideration of predicting geomagnetic storms on Earth. There exist numerous…

Solar and Stellar Astrophysics · Physics 2019-11-13 Dan Aksim , Alexey Melnikov , Dmitry Pavlov , Sergey Kurdubov

In February 2011 we proposed a NASA Explorer Mission of Opportunity program to develop and operate a large-aperture ultraviolet coronagraph spectrometer called the Coronal Physics Investigator (CPI) as an attached International Space…