Results 51 to 60 of about 8,745 (214)

Investigation of Phase Shift and Travel Time of Acoustic Waves in the Lower Solar Atmosphere Using Multiheight Velocities

The Astrophysical Journal
We report and discuss the phase shift and phase travel time of low-frequency ( ν < 5.0 mHz) acoustic waves estimated within the photosphere and photosphere–chromosphere interface regions, utilizing multiheight velocities in the quiet Sun.
Hirdesh Kumar, Brajesh Kumar, Shibu K. Mathew, A. Raja Bayanna, S. P. Rajaguru   +4 more
doaj   +1 more source

Ryugu reference project: Recommendations from the measurement definition team

Meteoritics &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, Guillaume Avice, Henner Busemann, Nicolas Dauphas, Daniel P. Glavin, Ashley J. King, Thorsten Kleine, Katharina Lodders, Frederic Moynier, Maria Schönbächler, Yoshinori Takano, Kun Wang, Hikaru Yabuta, Yuma Enokido, Ryota Fukai, Shogo Tachibana, Tomohiro Usui   +16 more
wiley   +1 more source

TURBULENT DIFFUSION IN THE PHOTOSPHERE AS DERIVED FROM PHOTOSPHERIC BRIGHT POINT MOTION

The Astrophysical Journal, 2011
On the basis of observations of solar granulation obtained with the New Solar Telescope (NST) of Big Bear Solar Observatory, we explored proper motion of bright points (BPs) in a quiet sun area, a coronal hole, and an active region plage. We automatically detected and traced bright points (BPs) and derived their mean-squared displacements as a function
ABRAMENKO V. I, CARBONE, Vincenzo, YURCHYSHYN V, GOODE P. R, STEIN R. F, LEPRETI, Fabio, CAPPARELLI V, VECCHIO A.   +7 more
openaire   +3 more sources

Spectral Irradiance Observations and Projections for Solar Cycle 25

Earth 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, Sergey V. Marchenko, Judith L. Lean, Odele Coddington   +3 more
wiley   +1 more source

Granular Spots in the Solar Photosphere

The Astrophysical Journal Letters
Granulation and sunspots are fundamental structures of the solar photosphere. Here, we discover the universal dark regions in TiO images from the New Vacuum Solar Telescope and name them granular spots (GSs).
Shaoxuan Tong, Jun Zhang, Zhenyu Jin
doaj   +1 more source

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

Journal 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, Eunjin Choi, Kyoung‐Joo Hwang, Kyunghwan Dokgo   +3 more
wiley   +1 more source

A High-resolution, Inversion-based Synoptic Study of Solar Granulation

The Astrophysical Journal
The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun’s surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well known.
James W. Crowley, Ivan Milić, Gianna Cauzzi, Kevin Reardon   +3 more
doaj   +1 more source

Reconstructing Historical Solar Indices for Predicting Past Space Weather Events

Space 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, Denny M. Oliveira, Theodosios Chatzistergos, Gangkai Poh, Eftyhia Zesta   +4 more
wiley   +1 more source

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

Space 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, Yash Parlikar, Shaela I. Jones, Charles N. Arge   +3 more
wiley   +1 more source

Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts

The Astrophysical Journal
The prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal
Ding-Fang Hu, Jin-Jun Geng, Hao-Xuan Gao, Jing-Zhi Yan, Xue-Feng Wu   +4 more
doaj   +1 more source