Results 31 to 40 of about 9,046 (214)

Optimization Algorithm for Determining the Source Surface Radius Based on Parker Solar Probe In Situ Measurements From Encounters 1 to 19

open access: yesJournal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 4, August 2026.
Abstract The Potential Field Source Surface (PFSS) extrapolation is a method for estimating the large scale coronal magnetic field from photospheric magnetograms. The source surface serves as the outer boundary of its solution domain, and is typically a spherical surface.
Shiouhe Wang   +4 more
wiley   +1 more source

Apparent Photosphere of Massive Accretion-Disk Winds

open access: yes, 2021
We examined the observational appearance of highly optically thick winds from supercritical accretion disks, while especially focusing on the shape of a “photosphere" of the wind. When a massive wind blows from an accretion disk, the optical depth of the
FUKUE, Jun   +2 more
core  

The UK Met Office’s Coronal Mass Ejection (CME) Ensemble Prediction System

open access: yesSpace Weather, Volume 24, Issue 7, July 2026.
Abstract We describe the 24‐member Coronal Mass Ejection (CME) ensemble prediction system that is used operationally at the UK's Met Office Space Weather Operations Center (MOSWOC) to forecast the arrival time of CMEs at Earth. The ensemble system was built on ad‐hoc assumptions and there is the need to investigate whether the technique can be improved
Siegfried Gonzi   +8 more
wiley   +1 more source

Diver photographed from Williamson Photosphere, 1914

open access: yes, 2014
Native diver underwater photographed from the Williamson Photosphere in the Bahamas, 1914.

core   +3 more sources

Noble gases and nitrogen in material from asteroid Bennu

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 7, Page 1593-1609, July 2026.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty   +7 more
wiley   +1 more source

Solar photosphere and convection

open access: yes, 2003
Photosphere ...
Nordlund, Å.
core   +1 more source

Quantifying the Impact of Relativistic Precession on Tidal Disruption Event Light Curves

open access: yesAstronomische Nachrichten, Volume 347, Issue 5, June 2026.
ABSTRACT The tidal field of a black hole can turn a star into a gas stream whose orbit can precess, especially if the a black hole is rapidly spinning. In this work, we investigate the impact of precession on the light curves of tidal disruption events (TDE).
Diego Calderón   +4 more
wiley   +1 more source

THE SUN’S PHOTOSPHERIC CONVECTION SPECTRUM [PDF]

open access: yesThe Astrophysical Journal, 2015
Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different analysis methods are used to separately determine spectral coefficients representing the poloidal flows, the toroidal
David H. Hathaway   +3 more
openaire   +2 more sources

Hidden No More: Spotlight on Tidal Disruption Events in Active Galactic Nuclei

open access: yesAstronomische Nachrichten, Volume 347, Issue 5, June 2026.
ABSTRACT Tidal disruption events (TDEs) are typically discovered in previously quiescent galaxies. However, earlier studies have revealed a handful of TDEs occurring in pre‐existing active galactic nuclei (AGN). We discuss AT2019aalc, a promising TDE candidate in an AGN, and compare it to similar sources.
Patrik Milán Veres
wiley   +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

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