Results 61 to 70 of about 1,069,804 (194)

Can We Distinguish the Source Region Location of Filament/Prominence Eruptions from the Sun-as-a-star Hα Spectrum?

open access: yesThe Astrophysical Journal
Solar filament/prominence eruptions can significantly perturb geospace when originating from favorable source locations and directions. While stellar analogs have been recently reported, the disk locations and magnetic environments of their source ...
Junyi Zhang   +9 more
doaj   +1 more source

Observations of a solar flare and filament eruption in Lyman $\mathsf{\alpha}$ and X-rays [PDF]

open access: yesAstronomy & Astrophysics, 2009
We aim to characterise the appearance and behaviour of a flare and filament ejection which occurred on 8th September 1999 and was observed by TRACE in L-alpha as well as by the Yohkoh Soft and Hard X-ray telescopes. We explore the flare energetics and its spatial and temporal evolution.
da Costa, F. Rubio   +3 more
openaire   +2 more sources

New Observations of Cosmic Noise Absorption in the South American Magnetic Anomaly (SAMA) Using a Next‐Generation Riometer

open access: yesSpace Weather, Volume 24, Issue 7, July 2026.
Abstract This study reports the first observations of cosmic noise power (CNP) and cosmic noise absorption (CNA) obtained with a next‐generation riometer installed at the Southern Space Observatory (SSO/INPE) in Brazil, located within the South American Magnetic Anomaly (SAMA).
J. Moro   +11 more
wiley   +1 more source

Fast Downflows Observed during a Polar Crown Filament Eruption

open access: yesThe Astrophysical Journal
Solar filaments can undergo eruptions that result in the formation of coronal mass ejections, which can significantly impact planetary space environments. Observations of eruptions involving polar crown filaments, situated in the polar regions of the Sun,
Zheng Sun   +4 more
doaj   +1 more source

Mini-filaments – small-scale analogues of solar eruptive events? [PDF]

open access: yesProceedings of the International Astronomical Union, 2008
AbstractMini-filaments are a small-scale phenomenon of the solar chromosphere, which frequently occur across the entire disk (see e.g. Wang, Li, Denker, et al. 2000). They share a variety of characteristics with their larger-scale cousins and may serve as a proxy for more complex systems. They play an important role in the energy and mass supply to the
Carsten Denker, Alexandra Tritschler
openaire   +1 more source

Droughts and human impact in the ancient Uaymil region of the Maya lowlands inferred from a 2800‐year sedimentary archive at Lake Kaná, Mexico

open access: yesBoreas, Volume 55, Issue 3, Page 768-789, July 2026.
The relationship between the climate and societal transformation in Maya lowlands has long been debated, particularly the role of drought in shaping the civilization trajectory during the Classic Period. A high‐resolution, multi‐proxy, geochemical record from Lake Kaná, located in the underexplored Uaymil region of the Yucatán Peninsula in Mexico ...
Haydar B. Martinez‐Dyrzo   +5 more
wiley   +1 more source

Solar Flares Triggered by a Filament Peeling Process Revealed by High-resolution GST Hα Observations

open access: yesThe Astrophysical Journal Letters
The dynamic structures of solar filaments prior to solar flares provide important physical clues about the onset of solar eruptions. Observations of those structures under subarcsecond resolution with high cadence are rare.
Mia Mancuso   +3 more
doaj   +1 more source

Comparing Solar Structure Detection Methods in SDO/AIA Observations and the Application to Raw Uncalibrated Data

open access: yesJournal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 3, June 2026.
Abstract Recent advances in solar physics increasingly rely on automated identification of coronal structures using machine learning. Yet most studies emphasize scientific performance without evaluating feasibility for onboard deployment to prioritize downlink observations.
P. Gonidakis   +11 more
wiley   +1 more source

Sun-as-a-star Spectroscopic Observations of the Line-of-sight Velocity of a Solar Eruption on 2021 October 28

open access: yesThe Astrophysical Journal, 2022
The propagation direction and true velocity of a solar coronal mass ejection, which are among the most decisive factors for its geo-effectiveness, are difficult to determine through single-perspective imaging observations. Here we show that Sun-as-a-star
Yu Xu   +5 more
doaj   +1 more source

Identifying and Predicting Coronal Mass Ejection Occurrence: Observational Checklists for Space Weather Forecasters

open access: yesSpace Weather, Volume 24, Issue 6, June 2026.
Abstract Ejections of magnetized plasma from the Sun, known as coronal mass ejections, can drive major geomagnetic activity if Earth‐directed, and are therefore monitored by space weather forecasters. The current focus being the forecast of the arrival time of a coronal mass ejection at Earth and the level of geomagnetic impact.
L. M. Green   +7 more
wiley   +1 more source

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