Research Note

Stereoscopic investigation on plasma density fluctuations in the outer solar corona

¹ National Institute for Astrophysics (INAF), Astrophysical Observatory of Torino, via Osservatorio 20, 10025 Pino Torinese, Italy
e-mail: telloni@oato.inaf.it
² National Institute for Astrophysics (INAF), Astrophysical Observatory of Catania, via S. Sofia 78, 95123 Catania, Italy

Received: 1 October 2013
Accepted: 17 February 2014

Abstract

This research note extends a previous work focused on the 2D reconstruction of the spatial distribution and temporal evolution of the plasma density fluctuations in the outer solar corona and based on STEREO COR1-A white-light observations. By using the corresponding total brightness images obtained in the same observational period with the coronagraph COR1-B onboard the “Behind” twin STEREO-B spacecraft, and adopting the same methodological approach as for COR1-A data, it was possible to confirm the results of the previous work and argue for the 3D configuration of the fluctuations of the coronal plasma. This provides further evidence in support of a scenario in which the fluctuating features, which are recurrent and spatially coherent, are localized along the magnetic field lines and points out the crucial role played by the 3D magnetic field topology in the confinement and evolution of the plasma density fluctuations.