منابع مشابه
Spectroscopic Diagnostics of Polar Coronal Plumes
Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these observations, especially from SUMER/SOHO, but also from EUVI/STEREO, we deduce densities, temperatures, and abundance anomalies in plumes and inter-plume regions, a...
متن کاملMagnetohydrodynamic waves in coronal polar plumes.
Polar plumes are cool, dense, linear, magnetically open structures that arise from predominantly unipolar magnetic footpoints in the solar polar coronal holes. As the Alfvén speed is decreased in plumes in comparison with the surrounding medium, these structures are natural waveguides for fast and slow magnetoacoustic waves. The simplicity of the geometry of polar plumes makes them an ideal tes...
متن کاملSlow Magnetosonic Waves in Coronal Plumes
Recent observations of polar plumes in the southern solar coronal hole by the Extreme-Ultraviolet Imaging Telescope (EIT) on board the SOHO spacecraft show signatures of quasi-periodic compressional waves with periods of 10È15 minutes. The relative wave amplitude was found to increase with height in the plumes up to about 1.2 Using a one-dimensional linear wave equation for the magnetosonic R _...
متن کاملAn MHD model for solar coronal plumes
Solar coronal plumes are modelled by solving the steady, ideal, 2-D, magnetohydrodynamic (MHD) equations and assuming azimuthal symmetry around the plume axis. Since magnetic fields are believed to play an essential role in plume formation and structure, a self-consistent method of linearisation of the MHD equations with respect to the magnetic field has been considered here. This consists of t...
متن کاملObservation of Quasi-periodic Compressive Waves in Solar Polar Plumes
On 1996 March 7, the Solar and Heliospheric Observatory spacecraft conducted a multi-instrument campaign to observe polar plumes in the south polar coronal hole. Recent time-domain analyses of EUV Imaging Telescope images from that campaign show filamentary substructure in the plumes, on a length scale of ∼50, which changes on timescales of a few minutes, and coherent quasi-periodic perturbatio...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1967
ISSN: 0004-6256
DOI: 10.1086/110457