Astrophysical: Solar activity

  • Publication
    Temporal and center-to-limb variations of the K I 769.9 NM line profiles in quiet and active solar regions
    The temporal and spatial behaviour of the K I 769.9 nm solar line are investigated using several series of high spectral resolution low-noise photoelectric...
  • Publication
    The global oscillation spectrum of the sun. I - Analysis of daily power spectra of velocity measurements
    Daily observations of solar global oscillations using a resonant scattering spectrometer have been obtained by observing integral sunlight during the summer...
  • News
    The IAC presents the video of the POLMAG project
    The IAC presents a public outreach video about the project “Polarized Radiation Diagnostics for Exploring the Magnetism of the Outer Solar Atmosphere” (POLMAG)...
  • Publication
    The low L solar p-mode spectrum at maximum and minimum solar activity
    Velocity measurements of disc integrated sunlight obtained at the Observatorio del Teide (Izana) from 1980 throughout 1989 are used to find the frequencies and...
  • Publication
    The motion of magnetic flux tubes in the convection zone and the subsurface origin of active regions
    The rise of kink-unstable magnetic flux tubes through the solar convection zone is discussed with a view to explaining the subsurface origin of active regions...
  • Publication
    The observation of intrinsically different emergences for large and small active regions
    The analysis of high-resolution H-alpha and white-light observations on the emergence of 73 active regions shows an intrinsically different behavior for both...
  • Publication
    The observed background solar velocity noise
    Using accurate radial velocity observations of integral sunlight, the background solar velocity noise has been measured at different frequencies of interest for...
  • Publication
    The profuse optically-thin irregularities of the photospheric magnetic fields
    The highly irregular nature of most photospheric magnetic fields is analyzed here, trying to emphasize the connection between photospheric fluctuations and...
  • Publication
    The role of activity complexes in the distribution of solar magnetic fields.
    Using published data on the large-scale distribution of solar activity, the authors conclude that the longlived coronal holes are formed and maintained by the...