Search Publications
The 17 April 2021 widespread solar energetic particle event
Holmström, M.; Grande, M.; Palmerio, E. +46 more
Context. A complex and long-lasting solar eruption on 17 April 2021 produced a widespread solar energetic particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere that covered distances to the Sun from 0.42 to 1 au: BepiColombo, Parker Solar Probe, Solar Orbiter, STEREO A, and near-Earth space…
Multiple injections of energetic electrons associated with the flare and CME event on 9 October 2021
Vainio, R.; Wiegelmann, T.; Krupar, V. +12 more
Context. We study the solar energetic particle (SEP) event observed on 9 October 2021 by multiple spacecraft, including Solar Orbiter. The event was associated with an M1.6 flare, a coronal mass ejection, and a shock wave. During the event, high-energy protons and electrons were recorded by multiple instruments located within a narrow longitudinal…
Type II radio bursts and their association with coronal mass ejections in solar cycles 23 and 24
Kilpua, E. K. J.; Kumari, A.; Morosan, D. E. +1 more
Context. Meter-wavelength type II solar radio bursts are thought to be the signatures of shock-accelerated electrons in the corona. Studying these bursts can give information about the initial kinematics, dynamics, and energetics of coronal mass ejections (CMEs) in the absence of white-light observations.
Aims: We investigate the occurrence o…
Rotation and interaction of the CMEs of September 8 and 10, 2014, tested with EUHFORIA
Poedts, Stefaan; Scolini, Camilla; Schmieder, Brigitte +1 more
Context. Solar coronal mass ejections (CMEs) can catch up and interact with preceding CMEs and solar wind structures to undergo rotation and deflection during their propagation. Aim. We aim to show how the interactions of a CME in the corona and heliosphere can play a significant role in altering its geoeffectiveness as predicted at the time of it…
Solar energetic electron events measured by MESSENGER and Solar Orbiter. Peak intensity and energy spectrum radial dependences: Statistical analysis
Lario, D.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +10 more
Context. We present a list of 61 solar energetic electron (SEE) events measured by the MESSENGER mission and the radial dependences of some parameters associated with these SEE events. The analysis covers the period from 2010 to 2015, when the heliocentric distance of MESSENGER varied between 0.31 and 0.47 au. We also show the radial dependences f…
Temporal variation of the photometric magnetic activity for the Sun and Kepler solar-like stars
García, R. A.; Mathur, S.; Jiménez, A. +9 more
Context. The photometric time series of solar-like stars can exhibit rotational modulation, that is, brightness variations due to active regions co-rotating with the stellar surface. These signatures allow us to constrain properties of stellar rotation and magnetic activity.
Aims: In this work we investigate the behavior, particularly the var…
A type II solar radio burst without a coronal mass ejection
Vainio, R.; Kilpua, E. K. J.; Kumari, A. +2 more
Context. The Sun produces the most powerful explosions in the Solar System, solar flares, which can also be accompanied by large eruptions of magnetised plasma, coronal mass ejections (CMEs). These processes can accelerate electron beams up to relativistic energies through magnetic reconnection processes during solar flares and CME-driven shocks. …
Imaging-spectroscopy of a band-split type II solar radio burst with the Murchison Widefield Array
Gallagher, Peter T.; Carley, Eoin P.; Oberoi, Divya +1 more
Type II solar radio bursts are caused by magnetohydrodynamic (MHD) shocks driven by solar eruptive events such as coronal mass ejections (CMEs). Often, both fundamental and harmonic bands of type II bursts are split into sub-bands, which are generally believed to be coming from upstream and downstream regions of the shock; however, this explanatio…
Image enhancement with wavelet-optimized whitening
Auchère, F.; Buchlin, É.; Soubrié, E. +1 more
Context. Due to its physical nature, the solar corona exhibits large spatial variations of intensity that make it difficult to simultaneously visualize the features present at all levels and scales. Many general-purpose and specialized filters have been proposed to enhance coronal images. However, most of them require the ad hoc tweaking of parame…
Revisiting empirical solar energetic particle scaling relations. I. Solar flares
Veronig, Astrid M.; Papaioannou, Athanasios; Herbst, Konstantin +3 more
Aims: The possible influence of solar superflares on the near-Earth space radiation environment are assessed through the investigation of scaling laws between the peak proton flux and fluence of solar energetic particle (SEP) events with the solar flare soft X-ray peak photon flux.
Methods: We compiled a catalog of 65 well-connected (W20…