Results 11 to 20 of about 513 (133)

Spectral variability of photospheric radiation due to faculae [PDF]

Astronomy & Astrophysics, 2017
Context. Stellar spectral variability on timescales of a day and longer, arising from magnetic surface features such as dark spots and bright faculae, is an important noise source when characterising extra-solar planets. Current 1D models of faculae do not capture the geometric properties and fail to reproduce observed solar facular contrasts ...
Charlotte M. Norris, Benjamin Beeck, Yvonne C. Unruh, Sami K. Solanki, Natalie A. Krivova, Kok Leng Yeo   +5 more
openaire   +4 more sources

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

Space 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, D. R. Jackson, F.‐X. Bocquet, V. J. Pizzo, E. Adamson, G. Millward, A. R. Marble, D. Odstrcil, C. N. Arge   +8 more
wiley   +1 more source

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &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, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Centre-to-limb properties of small, photospheric quiet-Sun jets [PDF]

Astronomy & Astrophysics, 2015
9 pages, 9 ...
Rubio da Costa, F., Solanki, S., Danilovic, S., Hirzberger, J., Martinez-Pillet, V.   +4 more
openaire   +3 more sources

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

Astronomische 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

MODELING THE SUN’S SMALL-SCALE GLOBAL PHOTOSPHERIC MAGNETIC FIELD [PDF]

The Astrophysical Journal, 2016
ABSTRACT We present a new model for the Sun’s global photospheric magnetic field during a deep minimum of activity, in which no active regions emerge. The emergence and subsequent evolution of small-scale magnetic features across the full solar surface is simulated, subject to the influence of a global supergranular flow pattern ...
K. A. Meyer, D. H. Mackay
openaire   +3 more sources

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

Journal 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, F. Carella, E. Dineva, H‐J. Jeong, P. Antunes, A. Podobas, S. Raptis, V. Toy‐Edens, M. Jin, S. Poedts, J. Magdalenic, G. Miloshevich   +11 more
wiley   +1 more source

Search for photospheric footpoints of quiet Sun transition region loops [PDF]

Astronomy & Astrophysics, 2007
CONTEXT:The footpoints of quiet Sun Transition Region (TR) loops do not seem to coincide with the photospheric magnetic structures appearing in traditional low-sensitivity magnetograms. AIMS: To look for the so-far unidentified photospheric footpoints of TR loops using G-band bright points (BPs) as proxies for photospheric magnetic field concentrations.
Sánchez Almeida, J., Teriaca, L., Sütterlin, P., Sparado, D., Schühle, U., Rutten, R.J.   +5 more
openaire   +5 more sources

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

Space 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, A. W. James, N. Ngampoopun, S. L. Yardley, K. Waite, E. K. Mottram, J. Hernandez Camero, J. O'kane   +7 more
wiley   +1 more source

The Sun's Global Photospheric and Coronal Magnetic Fields: Observations and Models [PDF]

Living Reviews in Solar Physics, 2012
61 pages, 18 figures.
Mackay, Duncan Hendry, Yeates, Anthony Robinson   +1 more
openaire   +5 more sources