Search Publications
Models of solar surface dynamics: impact on eigenfrequencies and radius
Morel, P.; Turck-Chièze, S.; Piau, L. +3 more
We study the effects of different descriptions of the solar surface convection on the eigenfrequencies of p modes. 1D evolution calculations of the whole Sun and 3D hydrodynamic and magnetohydrodynamic simulations of the current surface are performed. These calculations rely on realistic physics. Averaged stratifications of the 3D simulations are …
Helioseismic measurements in the solar envelope using group velocities of surface waves
Vorontsov, S. V.; Baturin, V. A.; Ayukov, S. V. +1 more
At intermediate- and high-degree l, solar p and f modes can be considered as surface waves. Using variational principle, we derive an integral expression for the group velocities of the surface waves in terms of adiabatic eigenfunctions of normal modes, and address the benefits of using group-velocity measurements as a supplementary diagnostic too…
Flare on 2011 September 22 and coronal mass ejection from observations in the He I 10830-Å line
Marchenko, G. P.; Akimov, L. A.; Belkina, I. L.
In this paper, we present the results from a study of the X1.4/2N flare and the accompanying coronal mass ejection (CME) on 2011 September 22 from observations of the spectral region around the He I 10830-Å line. In the study, 20 He I 10830-Å line images of the full disc of the Sun and 20 dopplerograms were obtained. Parts of the active region (AR…
A filament eruption with an apparent reshuffle of endpoints
Filippov, Boris
A filament eruption during 2010 April 30-May 1, which shows the reconnection of one filament leg with a region far away from its initial position, is analysed. Observations from three viewpoints are used for measurements of endpoint coordinates as precise as possible. The northern leg of the erupting prominence loop `jumps' laterally to a latitude…