Results 61 to 70 of about 427 (166)

The Temperature and Emission Measure Distribution in the Quiet and Active Solar Corona: A Bayesian Approach

The Astrophysical Journal, 2022
Abstract The reconstruction of the differential emission measure (DEM) from observations of spectral line intensities provides information on the temperature distribution of the emission measure in the region observed. The inversion process is known to be highly unstable, and it has been necessary to provide additional constraints, such ...
openaire   +2 more sources

Natural Generation of Alfvén Waves from Three-dimensional Bursty Interchange Magnetic Reconnection in the Solar Corona

The Astrophysical Journal Letters
Alfvén waves play a significant role in solar coronal heating, solar wind acceleration, and Alfvénic turbulence formation. As a fundamental process, magnetic reconnection has long been credited as a crucial source of Alfvén waves.
Liping Yang, Jiansen He, Xueshang Feng, Daniel Verscharen, Fan Guo, Hui Li, Hui Tian, Wenya Li, Fang Shen, Chuanpeng Hou, Mijie Shi, Honghong Wu, Ming Xiong   +12 more
doaj   +1 more source

Characterizing Patterns of Resurfacing on Venus With Volcanoes and Coronae

Journal of Geophysical Research: Planets, Volume 131, Issue 5, May 2026.
Abstract One of the major research questions for Venus is the manner in which it resurfaces itself, with a near‐random distribution of a relatively few craters providing the only age constraints for the planet's surface. We use volcanoes and their temporal and spatial relationships to coronae to characterize patterns of coronal resurfacing for ...
Nicholas J. Montiel, Barbara De Toffoli
wiley   +1 more source

How Does the Definition of a Geomagnetic Storm Affect the Contents of the Resulting Storm List?

Space Weather, Volume 24, Issue 5, May 2026.
Abstract A geomagnetic storm is a significant and prolonged disturbance of the Earth's magnetic field caused by an enhancement of the ring current. Storms are typically identified using magnetic field measurements from multiple ground‐based magnetometers, and the corresponding dates and times of multiple storms can be collated to form a storm list ...
Atlas M. Patrick, John C. Coxon, Sarah N. Bentley, Maria‐Theresia Walach, Kyle R. Murphy, I. Jonathan Rae, Isobel S. Lockley   +6 more
wiley   +1 more source

Ubiquitous Small-scale Extreme-ultraviolet Upflow-like Events above Network Regions Observed by the Solar Orbiter/Extreme Ultraviolet Imager

The Astrophysical Journal
Universal small-scale solar activity in the quiet region is suggested to be a potential source of solar wind and the upper solar atmosphere. Here, with the high-resolution 174 Å imaging observations from the Solar Orbiter/Extreme Ultraviolet Imager, we ...
Yadan Duan, Hechao Chen, Zhenyong Hou, Zheng Sun, Yuandeng Shen   +4 more
doaj   +1 more source

PRELIMINARY RESULTS OF INTERFEROMETRIC OBSERVATIONS OF THE QUIET SUN AT THE FREQUENCIES 8 – 32 MHZ

Odessa Astronomical Publications, 2018
We studied a radio emission of the quiet Sun at decameter wavelengths to determine its angular dimensions. Observations were conducted using interferometers composed of antenna sections of the UTR-2 radio telescope.
V. A. Shepelev, V. N. Melnik, R. V. Vashchishin   +2 more
doaj   +1 more source

Mars' Ionospheric Response to the Onset and Early Phase of 20 May 2024 Solar Flare

Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.
Abstract Solar extreme ultraviolet (EUV, 10–100 nm) and X‐ray (<10 nm) photons are the primary ionization source for the dayside Mars ionosphere. Their fluxes, especially at short wavelengths, increase significantly during solar flares. Among the series of solar flares and solar storms encountered by Earth and Mars in May 2024, one of the strongest ...
Shaosui Xu, Edward M. Thiemann, Ali Rahmati, David L. Mitchell, Kathleen G. Hanley, Wenyi Sun, James P. McFadden, Christopher M. Fowler, Mehdi Benna, Christian X. Mazelle, Shannon M. Curry   +10 more
wiley   +1 more source

Thread Displacement and Intensity Oscillations in a Quiescent Prominence

The Astrophysical Journal
In this paper, we investigate the thread displacement and intensity oscillations in a quiescent prominence observed by New Vacuum Solar Telescope at the H α line center on 2019 October 31.
Yuxiang Song, Zongjun Ning, Dong Li, Fanpeng Shi, Jun Xu, Yuzhi Yang   +5 more
doaj   +1 more source

Coronal Cells in Coronal Holes: Systematic Analysis and Implications for Coronal Evolution

The Astrophysical Journal
Using advanced processing techniques, we analyze high-cadence, high-resolution extreme-ultraviolet images and show that, throughout the solar cycle, midlatitude coronal holes (CHs) are made up of ubiquitous and space-filling funnel-shaped structures (or ...
Nathalia Alzate, Simone Di Matteo, Aleida Higginson   +2 more
doaj   +1 more source

Periodic Variations in Visible Light Brightness as Tracers of Fine Coronal Structures

The Astrophysical Journal
The quiescent or dynamic nature of fine-scale raylike features in the Sun corona, observed in visible light, is still an open question. Here, we show that most of the daily and hourly periodic variations in visible light brightness of the high corona (up
Nathalia Alzate, Simone Di Matteo
doaj   +1 more source