Search Publications
A coronal mass ejection encountered by four spacecraft within 1 au from the Sun: ensemble modelling of propagation and magnetic structure
Al-Haddad, Nada; Riley, Pete; Richter, Ingo +11 more
Understanding and predicting the structure and evolution of coronal mass ejections (CMEs) in the heliosphere remains one of the most sought-after goals in heliophysics and space weather research. A powerful tool for improving current knowledge and capabilities consists of multispacecraft observations of the same event, which take place when two or…
Hemispheric asymmetry of coronal bright point's number and area over solar cycles 23-24
Karachik, Nina V.; Minenko, Ekaterina P.
Temporal variations in the number and area of coronal bright points (CBPs) were studied separately in the Northern and Southern hemispheres over more than two solar cycles (years 1996-2022). Hemispheric asymmetry was identified in both the total number and area of CBPs, with differences reaching up to 15 per cent. Statistical analysis using Studen…
Two successive EUV waves and a transverse oscillation of a quiescent prominence
Li, Y.; Yan, X. L.; Zhang, Q. M. +4 more
In this paper, we carry out multiwavelength observations of two successive extreme-ultraviolet (EUV) waves originating from active region (AR) NOAA 13575 and a transverse oscillation of a columnar quiescent prominence on 2024 February 9. A hot channel eruption generates an X3.4 class flare and the associated full-halo coronal mass ejection (CME), …
A simple method to measure νmax for asteroseismology: application to 16 000 oscillating Kepler red giants
Li, Yaguang; Huber, Daniel; Bedding, Timothy R. +4 more
The importance of νmax (the frequency of maximum oscillation power) for asteroseismology has been demonstrated widely in the previous decade, especially for red giants. With the large amount of photometric data from CoRoT (Convection, Rotation, and planetary Transits), Kepler, and Transiting Exoplanet Survey Satellite, several automated…
The acoustic size of the Sun
Gough, D. O.; Takata, M.
Analysis of f-mode frequencies has provided a measure of the radius of the Sun which is lower, by a few hundredths per cent, than the photospheric radius determined by direct optical measurement. Part of this difference can be understood by recognizing that it is primarily the variation of density well beneath the photosphere of the star that dete…
Photospheric signatures of CME onset
Fletcher, L.; Romano, P.; MacTaggart, D. +2 more
Coronal mass ejections (CMEs) are solar eruptions that involve large-scale changes to the magnetic topology of an active region. There exists a range of models for CME onset which are based on twisted or sheared magnetic field above a polarity inversion line (PIL). We present observational evidence that topological changes at PILs, in the photosph…
Non-conventional approach for deriving the radial sizes of coronal mass ejections at different instances: discrepancies in the estimates between remote and in situ observations
Mishra, Wageesh; Agarwal, Anjali
Understanding the evolution of radial sizes and instantaneous expansion speeds of coronal mass ejections (CMEs) is crucial for assessing their impact duration on Earth's environment. We introduce a non-conventional approach to derive the CME's radial sizes and expansion speeds at different instances during its passage over a single-point in situ s…
Hemispheric analysis of the magnetic flux in regular and irregular solar active regions
Zhukova, A.
Studying the hemispheric distribution of active regions (ARs) with different magnetic morphologies may clarify the features of the dynamo process that is hidden under the photospheric level. The magnetic flux data for 3047 ARs from the CrAO catalogue (https://sun.crao.ru/databases/catalog-mmc-ars), between May 1996 and December 2021 (cycles 23 and…
Deciphering the evolution of thermodynamic properties and their connection to the global kinematics of high-speed coronal mass ejections using FRIS model
Wang, Yuming; Nieves-Chinchilla, Teresa; Mishra, Wageesh +3 more
Most earlier studies have been limited to estimating the kinematic evolution of coronal mass ejections (CMEs), and only limited efforts have been made to investigate their thermodynamic evolution. We focus on the interplay of the thermal properties of CMEs with their observed global kinematics. We implement the Flux rope Internal State model to es…
Probing solar wind velocity from simultaneous superior solar conjunction radio science experiments of BepiColombo and Akatsuki missions
Imamura, T.; Shiota, D.; Iess, L. +5 more
A radio link directly probing the inner solar corona offers the possibility to characterize solar wind properties, including velocity, density, turbulence, and even the axial ratio. In this study, we leveraged radiometric data obtained during a joint superior solar conjunction of the ESA/JAXA BepiColombo mission and the JAXA Akatsuki mission. Our …