Results 1 to 10 of about 11,108,449 (286)

The evolution of a spot–spot-type solar active region which produced a major solar eruption

open access: yesFrontiers in Astronomy and Space Sciences, 2023
Solar active regions are the main sources of large solar flares and coronal mass ejections. It is found that the active regions producing large eruptions usually show compact, highly sheared polarity inversion lines.
Lijuan Liu, Lijuan Liu, Lijuan Liu
doaj   +1 more source

Large Photospheric Doppler Shift in Solar Active Region 12673. I. Field-aligned Flows

open access: yesThe Astrophysical Journal, 2023
Delta ( δ ) sunspots sometimes host fast photospheric flows along the central magnetic polarity inversion line (PIL). Here we study the strong Doppler shift signature in the central penumbral light bridge of solar active region NOAA 12673.
Jiayi Liu   +5 more
doaj   +1 more source

Magnetic field variations and seismicity of solar active regions [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society: Letters, 2009
Abstract Dynamical changes in the solar corona have proven to be very important in inducing seismic waves into the photosphere. Different mechanisms for their generation have been proposed. In this work, we explore the magnetic field forces as plausible mechanisms to generate sunquakes as proposed by Hudson, Fisher & Welsch.
Martinez-Oliveros, J. C., Donea, A. -C.
openaire   +2 more sources

On the Origin of the Photospheric Magnetic Field

open access: yesThe Astrophysical Journal, 2022
This article presents results that challenge the paradigms that (1) the convection zone is the source of the radial magnetic field in the photosphere and (2) that coronal currents are neutralized from the perspective of the photosphere.
Peter W. Schuck   +3 more
doaj   +1 more source

Characterizing 3D Magnetic Structures in Sunspot Light Bridges

open access: yesThe Astrophysical Journal, 2023
Light bridges (LBs) are narrow structures dividing sunspot umbra, and their role in active region evolution is yet to be explored. We investigated the magnetic structure of the two LBs: a narrow LB (with width ∼810 km) and a considerably wider LB (2475 ...
Ju Jing   +5 more
doaj   +1 more source

The solar active region magnetic field and energetics [PDF]

open access: yesProceedings of the International Astronomical Union, 2010
AbstractMotivated by increasingly more advanced solar observations, we recently develop a method of coronal magnetic field extrapolation, especially for an active region (sunspot region). Based on a more complex variational principle, the principle of minimum (energy) dissipation rate (MDR), we adopt and solve a more complex equation governing the ...
Qiang Hu   +4 more
openaire   +1 more source

Magnetic Field Reconstruction in a Solar Active Region [PDF]

open access: yesSymposium - International Astronomical Union, 2001
Supposing coronal magnetic fields are in a force-free state from the chromosphere to the height of two solar radii, we reconstruct 3D force-free magnetic fields by making use of a new numerical technique, in which the fields are represented by a boundary integral equation based on a specific Green's function.
H. Wang, Y. Yan, T. Sakurai
openaire   +1 more source

A Strong-flare Prediction Model Developed Using a Machine-learning Algorithm Based on the Video Data Sets of the Solar Magnetic Field of Active Regions

open access: yesThe Astrophysical Journal Supplement Series, 2023
It is well accepted that the physical properties obtained from the solar magnetic field observations of active regions (ARs) are related to solar eruptions.
Jingjing Wang   +3 more
doaj   +1 more source

Light Bridge and Magnetic Field in a Solar Active Region

open access: yesThe Astrophysical Journal, 2022
Abstract Observational data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the multiwavelength simultaneous imaging system attached to the New Vacuum Solar Telescope located at Fuxian Lake, China are employed for the study of light bridges and magnetic fields in the active region NOAA 12529. Coronal
Huaning Wang   +4 more
openaire   +1 more source

Determination of the Topology Skeleton of Magnetic Fields in a Solar Active Region [PDF]

open access: yesChinese Journal of Astronomy and Astrophysics, 2008
13 pages, 7 figures, 1 ...
Zhao, Hui   +4 more
openaire   +2 more sources

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