Astrophysical: Sunspots

  • Publication
    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...
  • Publication
    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...
  • Publication
    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...
  • Publication
    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...
  • Publication
    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...
  • Publication
    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...
  • Publication
    Evolution of small-scale features at the penumbra-photosphere border
    Time series of images of a sunspot, acquired simultaneously in blue light and in G-band at the SVST, La Palma, are used to study horizontal motions of granules...
  • Publication
    Exploring the Sun's upper atmosphere with neural networks: Reversed patterns and the hot wall effect
    We have developed an inversion procedure designed for high-resolution solar spectro-polarimeters, such as those of Hinode and the DKIST. The procedure is based...
  • Publication
    FarNet-II: An improved solar far-side active region detection method
    Context. Activity on the far side of the Sun is routinely studied through the analysis of the seismic oscillations detected on the near side using helioseismic...