منابع مشابه
Small-scale flow field in a sunspot penumbra
We have measured velocity maps of a round sunspot near the center of the solar disk. We derive the small-scale velocity field of the penumbra in the deep photosphere. Superimposed on a radial outflow, we find up– and downflows, which are associated with bright and dark features: The flow in the dark component of the penumbra has a larger inclination angle with respect to the surface normal than...
متن کاملLong-term Evolution of Sunspot Magnetic Fields
Independent of the normal solar cycle, a decrease in the sunspot magnetic field strength has been observed using the Zeeman-split 1564.8nm Fe I spectral line at the NSO Kitt Peak McMath-Pierce telescope. Corresponding changes in sunspot brightness and the strength of molecular absorption lines were also seen. This trend was seen to continue in observations of the first sunspots of the new solar...
متن کاملEvolution of a Magnetic Flux Tube in a Sunspot Penumbra
The motion of an individual magnetic flux tube inside the penumbra of a sunspot is studied numerically. Here, we present preliminary results. The thin flux tube approximation together with a simplified radiative heat exchange with the surroundings is used to study the evolution of a flux tube embedded into a background given by a global magneto-static sunspot model. The investigation is underta...
متن کاملThe Three-Dimensional Structure of a Sunspot Magnetic Field
Here we report on observations of the three-dimensional structure of a sunspot magnetic field from the photosphere to the chromosphere, obtained with the new visible/infrared spectro-polarimeter SPINOR. The observations, interpreted with a non-LTE modeling technique, reveal a surprisingly complex topology with areas of opposite-sign torsion, suggesting that flux-ropes of opposite helicities may...
متن کاملThe dependence of the magnetic field strength of a sunspot umbra on its intensity and brightness temperature
A partial decrease of the convective energy by the magnetic field of a sunspot causes the temperature of the magnetized plasma to decrease and this leads to a magneto-hydrostatic equilibrium. Thus, we expect a strong relation between magnetic field strength of a sunspot and its temperature/brightness. Here, we investigate this relation in the umbra of the large sunspot in NOAA10930 using spectr...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2007
ISSN: 0004-637X,1538-4357
DOI: 10.1086/523102