Astrofísicas: Manchas solares

  • Publicación
    Differential rotation and the SPOT zones
    Doppler measurements, using the Capri magnetograph, of the latitudinal fine structure of the solar differential rotation have been carried out. The positions of...
  • Publicación
    Differential rotation of sunspot groups in the period from 1874 through 1976 and changes of the rotation velocity within the solar cycle
    An effort is made to determine the differential rotation of the sun on the basis of the complete sample (1874-1976) of the Greenwich Photoheliographic Results...
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    Direct Imaging of Fine Structure in the Chromosphere of a Sunspot Umbra
    High-resolution imaging observations from the Hinode spacecraft in the Ca II H line are employed to study the dynamics of the chromosphere above a sunspot. We...
  • Publicación
    Discovery of long-period magnetic field oscillations and motions in isolated sunspots
    We analyse the temporal evolution of the inclination component of the magnetic field vector for the penumbral area of 25 isolated sunspots. Compared to previous...
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    Downflowing umbral flashes as evidence of standing waves in sunspot umbrae
    Context. Umbral flashes are sudden brightenings commonly visible in the core of some chromospheric lines. Theoretical and numerical modeling suggests that they...
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    Evaluation of a Magnetic Field Inversion Method Using Only Stokes I
    We compare a method for inferring the photospheric vector magnetic field using only spectroscopy to a conventional method based on polarimetry. The magnetic...
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    Evershed Clouds as Precursors of Moving Magnetic Features around Sunspots
    The relation between the Evershed flow and moving magnetic features (MMFs) is studied using high-cadence, simultaneous spectropolarimetric measurements of a...
  • Publicación
    Evershed flow observed in neutral and singly ionized iron lines
    The amplitudes of the Evershed flow are measured using pairs of carefully selected Fe i and Fe ii spectral lines that are close in wavelength and registered...
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    Evidence for supersonic downflows in the photosphere of a delta sunspot
    We present polarization profiles observed with the High Altitude Observatory/National Solar Observatory (HAO/NSO) Advanced Stokes Polarimeter (ASP) that...