Search Publications
On the Mesoscale Structure of Coronal Mass Ejections at Mercury's Orbit: BepiColombo and Parker Solar Probe Observations
Dresing, Nina; Nieves-Chinchilla, Teresa; Weiss, Andreas J. +27 more
On 2022 February 15, an impressive filament eruption was observed off the solar eastern limb from three remote-sensing viewpoints, namely, Earth, STEREO-A, and Solar Orbiter. In addition to representing the most-distant observed filament at extreme ultraviolet wavelengths—captured by Solar Orbiter's field of view extending to above 6 R ⊙
Multispacecraft Observations of a Widespread Solar Energetic Particle Event on 2022 February 15–16
Holmström, M.; Lario, D.; Palmerio, E. +37 more
On 2022 February 15–16, multiple spacecraft measured one of the most intense solar energetic particle (SEP) events observed so far in Solar Cycle 25. This study provides an overview of interesting observations made by multiple spacecraft during this event. Parker Solar Probe (PSP) and BepiColombo were close to each other at 0.34–0.37 au (a radial …
The Width of Magnetic Ejecta Measured near 1 au: Lessons from STEREO-A Measurements in 2021–2022
Lugaz, Noé; Zhuang, Bin; Scolini, Camilla +7 more
Coronal mass ejections (CMEs) are large-scale eruptions with a typical radial size at 1 au of 0.21 au but their angular width in interplanetary space is still mostly unknown, especially for the magnetic ejecta (ME) part of the CME. We take advantage of STEREO-A angular separation of 20°–60° from the Sun–Earth line from 2020 October to 2022 August,…
The Loss of Starlink Satellites in February 2022: How Moderate Geomagnetic Storms Can Adversely Affect Assets in Low-Earth Orbit
Nandy, Dibyendu; Palmerio, Erika; Pal, Sanchita +4 more
On 3 February 2022, SpaceX launched 49 Starlink satellites, 38 of which unexpectedly de-orbited. Although this event was attributed to space weather, definitive causality remained elusive because space weather conditions were not extreme. In this study, we identify solar sources of the interplanetary coronal mass ejections that were responsible fo…
Differential Rotation of the Solar Chromosphere: A Century-long Perspective from Kodaikanal Solar Observatory Ca II K Data
Chatzistergos, Theodosios; Ermolli, Ilaria; Chatterjee, Subhamoy +5 more
Chromospheric differential rotation is a key component in comprehending the atmospheric coupling between the chromosphere and the photosphere at different phases of the solar cycle. In this study, we therefore utilize the newly calibrated multidecadal Ca II K spectroheliograms (1907-2007) from the Kodaikanal Solar Observatory (KoSO) to investigate…
Circular-ribbon flares and the related activities
Zhang, Qingmin
Solar flares are an impulsive increase of emissions as a result of impetuous release of magnetic free energy. This paper will present the recent progress on circular-ribbon flares (CRFs) and their related activities, including coronal jets, filaments, coronal mass ejections (CMEs), radio bursts, coronal dimmings, and coronal loop oscillations. Owi…
Observations of the 2022 September 5 Solar Energetic Particle Event at 15 Solar Radii
Mitchell, D. G.; McComas, D. J.; Bale, S. D. +27 more
On 2022 September 5, Parker Solar Probe (Parker) observed a large solar energetic particle (SEP) event at the unprecedented distance of only 15 R S from the Sun. The observations from the Integrated Science Investigation of the Sun (IS⊙IS) obtained over the course of this event are remarkably rich, and an overview is presented here. IS⊙…
A Pileup of Coronal Mass Ejections Produced the Largest Geomagnetic Storm in Two Decades
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
The largest geomagnetic storm in two decades occurred in 2024 May with a minimum D st of ‑412 nT. We examine its solar and interplanetary origins by combining multipoint imaging and in situ observations. The source active region, NOAA AR 13664, exhibited extraordinary activity and produced successive halo eruptions, which were responsib…
The multi-spacecraft high-energy solar particle event of 28 October 2021
Vainio, R.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +15 more
Aims: We studied the first multi-spacecraft high-energy solar energetic particle (SEP) event of solar cycle 25, which triggered a ground level enhancement on 28 October 2021, using data from multiple observers (Parker Solar Probe, STEREO-A, Solar Orbiter, GOES, SOHO, BepiColombo, and the Mars Science Laboratory) that were widely distributed t…
Connecting remote and in situ observations of shock-accelerated electrons associated with a coronal mass ejection
Jebaraj, I. C.; Vainio, R.; Kilpua, E. K. J. +7 more
Context. One of the most prominent sources for energetic particles in our Solar System are huge eruptions of magnetised plasma from the Sun, known as coronal mass ejections (CMEs), which usually drive shocks that accelerate charged particles up to relativistic energies. In particular, energetic electron beams can generate radio bursts through the …