Results 21 to 30 of about 513 (133)

Extreme Value Analysis of Solar Green‐Line Corona During the Time Interval 1939–2025

open access: yesSpace Weather, Volume 24, Issue 5, May 2026.
Abstract Predicting the probability of extreme solar events is critical to understanding how to mitigate risks associated with space weather disasters, as their occurrence can pose a threat to life and infrastructure on Earth or in near‐Earth orbit. In the present study, extreme value theory is applied to the daily modified coronal index (MCI) for the ...
Miao Wan   +6 more
wiley   +1 more source

CI chondrite Oued Chebeika 002 links asteroids Bennu and Ryugu to common parent body

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 5, Page 801-818, May 2026.
Abstract CI chondrites are a compositionally primitive group of meteorites that have undergone extensive aqueous alteration, providing insights into the evolution of primitive planetesimals. Oued Chebeika 002 is the most pristine CI chondrite to date.
Megan Broussard   +11 more
wiley   +1 more source

MAGNETIC UPFLOW EVENTS IN THE QUIET-SUN PHOTOSPHERE. I. OBSERVATIONS [PDF]

open access: yesThe Astrophysical Journal, 2015
12 pages, 6 figures, 2 ...
S. Jafarzadeh   +2 more
openaire   +3 more sources

Ryugu reference project: Recommendations from the measurement definition team

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 5, Page 819-848, May 2026.
Abstract Sample return missions play a significant role in planetary science by providing pristine extraterrestrial materials. JAXA's Hayabusa2 and NASA's OSIRIS‐REx missions have returned samples from the C‐type asteroids Ryugu and Bennu, respectively. The chemical and mineralogical compositions of these samples closely resemble those of CI chondrites,
Tetsuya Yokoyama   +16 more
wiley   +1 more source

PHOTOSPHERIC ABUNDANCES OF POLAR JETS ON THE SUN OBSERVED BYHINODE [PDF]

open access: yesThe Astrophysical Journal, 2015
Many jets are detected at X-ray wavelengths in the Sun's polar regions, and the ejected plasma along the jets has been suggested to contribute mass to the fast solar wind. From in-situ measurements in the magnetosphere, it has been found that the fast solar wind has photospheric abundances while the slow solar wind has coronal abundances. Therefore, we
Kyoung-Sun Lee   +2 more
openaire   +2 more sources

Spectral Irradiance Observations and Projections for Solar Cycle 25

open access: yesEarth and Space Science, Volume 13, Issue 4, April 2026.
Abstract The Ozone Monitoring Instrument (OMI) on the Aura satellite makes near‐daily measurements of solar spectral irradiance (SSI) at wavelengths between 265 and 500 nm for instrument calibration purposes. The low degradation and exceptional stability of OMI's calibration during its lifetime facilitates the creation of a new 18‐year OMI Version 7 ...
Matthew T. DeLand   +3 more
wiley   +1 more source

Reconstruction of Two‐Dimensional Magnetohydrodynamic and Hall Magnetohydrodynamic Equilibria in Space Using Physics‐Informed Neural Networks

open access: yesJournal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 2, April 2026.
Abstract We present a novel data analysis technique based on physics‐informed neural networks (PINNs) to reconstruct two‐dimensional (2D) magnetohydrodynamic (MHD) and Hall MHD equilibria in a space plasma from in situ spacecraft measurements. Our method incorporates the steady‐state MHD or Hall MHD equations—a set of partial differential equations ...
Hiroshi Hasegawa   +3 more
wiley   +1 more source

Reconstructing Historical Solar Indices for Predicting Past Space Weather Events

open access: yesSpace Weather, Volume 24, Issue 4, April 2026.
Abstract Modeling and forecasting the near‐Earth space environment, specifically the thermosphere, is particularly important because it affects the motion of low‐Earth orbit objects through atmospheric drag. Solar indices such as F10.7, S10.7, M10.7, and Y10.7 are commonly used as inputs to ionospheric and thermospheric density models.
Poshan Belbase   +4 more
wiley   +1 more source

Post‐Processing Probabilistic Forecasts of the Solar Wind by Data Mining Similar Scenarios

open access: yesSpace Weather, Volume 24, Issue 4, April 2026.
Abstract The solar wind speed at Earth is one of the most important parameters regarding the effects of space weather on society. Thus far, most approaches for predicting the solar wind speed produce a single‐value time series without uncertainty, or utilize ensemble methods which require custom calibration development.
Daniel E. da Silva   +3 more
wiley   +1 more source

Searching for Rotational X‐Ray Modulation on TIC 277539431

open access: yesAstronomische Nachrichten, Volume 347, Issue 3, March 2026.
ABSTRACT TIC 277539431, a fast rotating M7 dwarf, was detected to host the highest latitude flare to date at 81°$$ {81}^{{}^{\circ}} $$. Magnetic activity like stellar flares occurring at high latitude indicate occurrence of coronal loops at these latitudes on fully‐convective M dwarfs. In contrast, sunspots usually occur below 30°$$ {30}^{{}^{\circ}} $
Desmond Dsouza   +2 more
wiley   +1 more source

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