Analysis of the 5 min oscillatory photospheric motion

Solar Physics ◽  
1973 ◽  
Vol 31 (1) ◽  
Author(s):  
O.R. White ◽  
M.Y. Cha
Keyword(s):  
Photospheric Motion

The total photospheric motion field

Solar Physics ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 25-33 ◽  
Author(s):  
E. A. Gurtovenko
Keyword(s):  
Motion Field ◽  
Photospheric Motion

The determination of the velocity amplitude of the total photospheric motion field

Solar Physics ◽  
1974 ◽  
Vol 34 (2) ◽  
pp. 291-298 ◽  
Author(s):  
N. N. Kondrashova ◽  
E. A. Gurtovenko
Keyword(s):  
Motion Field ◽  
Velocity Amplitude ◽  
Photospheric Motion

scholarly journals LS IV — 14°116 : A Time-Resolved Spectroscopic Study

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
Pamela Martin ◽  
C. Simon Jeffery
Keyword(s):  
Radial Velocity ◽  
Spectroscopic Study ◽  
Optical Depth ◽  
Effective Temperature ◽  
Mode Instability ◽  
Instability Strip ◽  
Time Resolved ◽  
Blue Edge ◽  
Chemical Stratification ◽  
Photospheric Motion

AbstractLSIV-14 116 is a very unusual subdwarf B star. It pulsates non-radially with high-order g-modes, these pulsations are unexpected and unexplained, as the effective temperature is 6 000K hotter than the blue edge of the hot subdwarf g-mode instability strip. Its spectrum is enriched in helium which is not seen in either the V361 Hya (p-mode pulsators) or the V1093 Her stars (g-mode pulsators). Even more unusual is the 4 dex overabundance of zirconium, yttrium, and strontium. It is proposed that these over-abundances are a result of extreme chemical stratification driven by radiative levitation. We have over 20hrs of VLT/UVES spectroscopy from which we have obtained radial velocity curves for individual absorption lines. We are currently exploring ways in which to resolve the photospheric motion as a function of optical depth.

Analysis of the 5 min oscillatory photospheric motion

Solar Physics ◽  
1973 ◽  
Vol 31 (1) ◽  
Author(s):  
M.Y. Cha ◽  
O.R. White
Keyword(s):  
Photospheric Motion

scholarly journals A model of solar flares

1968 ◽  
Vol 35 ◽  
pp. 471-479 ◽  
Author(s):  
P. A. Sturrock
Keyword(s):  
Magnetic Field ◽  
Solar Flares ◽  
Transverse Dimension ◽  
Growth Time ◽  
Closed Field ◽  
Field Region ◽  
Tearing Mode ◽  
Magnetic Region ◽  
Field Lines ◽  
Photospheric Motion

A model of solar flares is proposed in which the preflare state comprises a bipolar magnetic-field structure associated with a bipolar photospheric magnetic region. At low heights, the magnetic-field lines are closed but, at sufficiently great heights, the lines are drawn out into an open structure comprising a bipolar flux tube containing a ‘neutral sheet’ or ‘sheet pinch’. Such a sheet pinch is probably related to a coronal streamer. The energy stored in the closed-field region is derived from photospheric motion whereas energy stored in the open-field region is derived from the non-thermal energy flux which heats the corona and drives the solar wind.The flare itself is identified with reconnection of magnetic field by the tearing-mode resistive instability. If the thickness of the sheet pinch is determined by resistive diffusion and a growth time of the bipolar region of order 1 day, the transverse dimension will be about 104 cm. The rise time of the tearing-mode instability is then a few seconds, compatible with the characteristic time of Type-III radio bursts. One can understand that the time-scale of the reconnection process is of order 102–103 sec if reconnection proceeds by the Petscheck mechanism, with the modification that resistive diffusion is replaced by the more rapid Bohm diffusion.The evolution of a flare, according to this model, appears to fit a number of the observational characteristics of flares.

scholarly journals Oscillatory Response of the 3D Solar Atmosphere to the Leakage of Photospheric Motion

Solar Physics ◽  
2009 ◽  
Vol 258 (2) ◽  
pp. 219-241 ◽  
Author(s):  
Viktor Fedun ◽  
Robert Erdélyi ◽  
Sergiy Shelyag
Keyword(s):  
Solar Atmosphere ◽  
Oscillatory Response ◽  
Photospheric Motion

scholarly journals Accretion disk flares

1986 ◽  
Vol 119 ◽  
pp. 411-412
Author(s):  
P. A. Sturrock ◽  
W. Yang
Keyword(s):  
Magnetic Field ◽  
Accretion Disk ◽  
Differential Rotation ◽  
Coronal Magnetic Field ◽  
Free State ◽  
Flare Activity ◽  
The Sun ◽  
Flux Condition ◽  
Photospheric Motion ◽  
The Magnetic Field

Flare activity on the sun may be attributed to the distortion of coronal magnetic field caused primarily by vortical (Shearing) photospheric motion. If an accretion disk is permeated by a magnetic field, the strong differential rotation of the disk will lead to similar stressing of the magnetosphere, and one may expect similar flare activity to occur. It is likely that the density of plasma in the maganetosphere is sufficiently large that the “frozen flux” condition is satisfied, and sufficiently small that the magnetic field will be substantially in the force-free state.

scholarly journals SUDDEN PHOTOSPHERIC MOTION AND SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15

2014 ◽  
Vol 782 (2) ◽  
pp. L31 ◽  
Author(s):  
Shuo Wang ◽  
Chang Liu ◽  
Na Deng ◽  
Haimin Wang
Keyword(s):  
Photospheric Motion
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