Results 11 to 20 of about 38,972 (307)

Properties of Flare-imminent versus Flare-quiet Active Regions from the Chromosphere through the Corona. I. Introduction of the AIA Active Region Patches (AARPs)

The Astrophysical Journal, 2023
We begin here a series of papers examining the chromospheric and coronal properties of solar active regions. This first paper describes an extensive data set of images from the Atmospheric Imaging Assembly on the Solar Dynamics Observatory curated for ...
Karin Dissauer, K. D. Leka, Eric L. Wagner   +2 more
doaj   +1 more source

Spectro-polarimetric Properties of Sunquake Sources in X1.5 Flare and Evidence for Electron and Proton Beam Impacts

The Astrophysical Journal, 2023
The first significant sunquake event of Solar Cycle 25 was observed during the X1.5 flare of 2022 May 10, by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory.
Alexander G. Kosovichev, Viacheslav M. Sadykov, John T. Stefan   +2 more
doaj   +1 more source

DISTRIBUTION OF ELECTRIC CURRENTS IN SOLAR ACTIVE REGIONS [PDF]

The Astrophysical Journal, 2014
6 pages, 5 figures, to appear in Astrophysical Journal ...
Török, T., Leake, J., E, Titov, V., Archontis, V., Mikić, Z., Linton, M., G, Dalmasse, K., Aulanier, G., Kliem, B.   +8 more
openaire   +5 more sources

High-resolution Observations of the Low Atmospheric Response to Small Coronal Heating Events in an Active Region Core

The Astrophysical Journal, 2023
High-resolution spectral observations of the lower solar atmosphere (chromosphere and transition region) during coronal heating events, in combination with predictions from models of impulsively heated loops, provide powerful diagnostics of the ...
Paola Testa, Helle Bakke, Luc Rouppe van der Voort, Bart De Pontieu   +3 more
doaj   +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

The 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, Bingxian Luo, Siqing Liu, Yue Zhang   +3 more
doaj   +1 more source

Sympathetic Partial Filament Eruptions Caused by the Interaction between Two Nearby Filaments

The Astrophysical Journal, 2023
To better understand the physical connections in sympathetic solar eruptions, we investigated the interaction between two nearby filaments and their successive partial eruptions in the active region (AR) NOAA 12866 on 2021 September 9 by using data from ...
Liping Yang, Xiaoli Yan, Zhike Xue, Jincheng Wang, Liheng Yang, Qiaoling Li, Zhe Xu, Yang Peng, Xia Sun, Xinsheng Zhang   +9 more
doaj   +1 more source

The Formation of a U-shaped Filament Due to the Successive Magnetic Reconnection between a Filament and Its Nearby Chromospheric Fibrils

The Astrophysical Journal, 2023
Although magnetic reconnection plays a key role in the formation of a solar filament, the detailed formation process is still ambiguous. Combining the observational data from the New Vacuum Solar Telescope and the Solar Dynamics Observatory, we analyzed ...
Liping Yang, Xiaoli Yan, Zhike Xue, Jincheng Wang, Liheng Yang, Zhe Xu, Qiaoling Li, Yian Zhou, Yang Peng, Xinsheng Zhang   +9 more
doaj   +1 more source

Evolution of Elemental Abundances in Hot Active Region Cores from Chandrayaan-2 XSM Observations

The Astrophysical Journal, 2023
The first ionization potential (FIP) bias, whereby elemental abundances for low-FIP elements in different coronal structures vary from their photospheric values and may also vary with time, has been widely studied.
Biswajit Mondal, Santosh V. Vadawale, Giulio Del Zanna, N. P. S. Mithun, Aveek Sarkar, Helen E. Mason, P. Janardhan, Anil Bhardwaj   +7 more
doaj   +1 more source

Solar Activity and Regional Climate [PDF]

Radiocarbon, 2001
We performed a statistical analysis of the data on summer temperature anomalies in northern Fennoscandia (8–1995 AD) and found that a 70–130-yr cycle is present in this series during most of the time period. A comparison of the reconstructed northern Fennoscandia temperature with different indicators of solar activity (Wolf numbers, the length of solar
M G Ogurtsov, G E Kocharov, M Lindholm, M Eronen, Yu A Nagovitsyn   +4 more
openaire   +1 more source

Confinedness of an X3.1-class Solar Flare Occurred in NOAA 12192: Analysis from Multi-instrument Observations

The Astrophysical Journal, 2023
The nonassociation of coronal mass ejections with high energetic flares is sparse. For this reason, the magnetic conditions required for the confinedness of major flares is a topic of active research.
N. Vasantharaju, F. Zuccarello, F. Ferrente, S. L. Guglielmino   +3 more
doaj   +1 more source