Astrophysical: Sunspots

  • Publication
    A statistical study of the geometrical Wilson effect
    An analysis has been carried out of the center-to-limb variation of the apparent sizes of the umbra, penumbra, and whole spot. It has revealed that the umbral...
  • Publication
    A Time-dependent Semiempirical Model of the Chromospheric Umbral Oscillation
    We present a time-dependent semiempirical model of the chromospheric umbral oscillation in sunspots. This model has been obtained by applying recently developed...
  • Publication
    Active region fine structure observed at 0.08 arcsec resolution
    Context. The various mechanisms of magneto-convective energy transport determine the structure of sunspots and active regions. Aims: We characterise the...
  • Publication
    Active Region Morphologies Selected from Near-side Helioseismic Data
    We estimate the morphology of near-side active regions using near-side helioseismology. Active regions from two data sets, Air Force Data Assimilative...
  • Publication
    Ambipolar Diffusion in the Lower Solar Atmosphere: Magnetohydrodynamic Simulations of a Sunspot
    Magnetohydrodynamic (MHD) simulations of the solar atmosphere are often performed under the assumption that the plasma is fully ionized. However, in the lower...
  • Publication
    An uncombed inversion of multiwavelength observations reproducing the net circular polarization in a sunspot's penumbra
    Context. The penumbra of sunspots has a complex magnetic field topology whose three-dimensional organization remains unclear after more than a century of...
  • Publication
    Anomalous Circular Polarization Profiles in Sunspot Chromospheres
    This paper presents a detailed description, analysis, and interpretation of the spectropolarimetric observations recently reported by Socas-Navarro, Trujillo...
  • Publication
    Are small-scale magnetic concentrations spatially coincident with bright facular points?
    The usually assumed identification of small-scale magnetic concentrations with bright facular or network points on the photosphere is observationally checked by...
  • Publication
    Are solar chromospheric fibrils tracing the magnetic field?
    Fibrils are thin elongated features visible in the solar chromosphere in and around magnetized regions. Because of their visual appearance, they have been...