A large coronal loop in the Algol system

Nature ◽  
2010 ◽  
Vol 463 (7278) ◽  
pp. 207-209 ◽  
Author(s):  
W. M. Peterson ◽  
R. L. Mutel ◽  
M. Güdel ◽  
W. M. Goss
Keyword(s):  
1992 ◽  
Vol 151 ◽  
pp. 303-306
Author(s):  
M. Taghi Edalati ◽  
Timothy Banks ◽  
Edwin Budding

Wide and narrow Hα lightcurves of R CMa were analysed using Wilson-Devinney (WD) and Information Limit Optimisation Technique (ILOT) approaches. A range of mass ratios, tested by both methods, led to an optimal estimate of around 0.45, at variance with the spectroscopic value. The distortion on the light curve affects the modelling, and so, in a second fitting, this was represented by a ‘hot spot’, associated with mass transfer effects. A semi-detached configuration was then derived. This is supported by the form of the Hα index variation, which has also been modelled. Although thus appearing as a ‘classical Algol’ system, R CMa retains its inherent peculiarity of low mass ratio with low period, which cannot be reconciled with conservative evolution scenarios.


Solar Physics ◽  
1987 ◽  
Vol 108 (1) ◽  
pp. 131-137 ◽  
Author(s):  
H. Aurass ◽  
J. Kurths ◽  
G. Mann ◽  
G. P. Chernov ◽  
M. Karlick�

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
M. S. Ruderman ◽  
N. S. Petrukhin ◽  
E. Pelinovsky

AbstractIn this article we study the plasma motion in the transitional layer of a coronal loop randomly driven at one of its footpoints in the thin-tube and thin-boundary-layer (TTTB) approximation. We introduce the average of the square of a random function with respect to time. This average can be considered as the square of the oscillation amplitude of this quantity. Then we calculate the oscillation amplitudes of the radial and azimuthal plasma displacement as well as the perturbation of the magnetic pressure. We find that the amplitudes of the plasma radial displacement and the magnetic-pressure perturbation do not change across the transitional layer. The amplitude of the plasma radial displacement is of the same order as the driver amplitude. The amplitude of the magnetic-pressure perturbation is of the order of the driver amplitude times the ratio of the loop radius to the loop length squared. The amplitude of the plasma azimuthal displacement is of the order of the driver amplitude times $\text{Re}^{1/6}$ Re 1 / 6 , where Re is the Reynolds number. It has a peak at the position in the transitional layer where the local Alfvén frequency coincides with the fundamental frequency of the loop kink oscillation. The ratio of the amplitude near this position and far from it is of the order of $\ell$ ℓ , where $\ell$ ℓ is the ratio of thickness of the transitional layer to the loop radius. We calculate the dependence of the plasma azimuthal displacement on the radial distance in the transitional layer in a particular case where the density profile in this layer is linear.


2006 ◽  
Vol 466 (1) ◽  
pp. 339-346 ◽  
Author(s):  
L. Bone ◽  
J. C. Brown ◽  
L. Fletcher ◽  
A. Veronig ◽  
S. White
Keyword(s):  

2018 ◽  
Vol 868 (2) ◽  
pp. 116 ◽  
Author(s):  
R. B. Dahlburg ◽  
G. Einaudi ◽  
I. Ugarte-Urra ◽  
A. F. Rappazzo ◽  
M. Velli

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