Astrophysical: Solar activity

  • Publication
    Instability and eruption of magnetic flux tubes in the solar convection zone
    We present a consistent model of storage, instability and dynamical eruption of magnetic flux tubes in the solar convection zone and underlying overshoot region...
  • Publication
    Long-term Spatial and Temporal Variations of Aurora Borealis Events in the Period 1700 - 1905
    Catalogues and other records of aurora-borealis events were used to study the long-term spatial and temporal variation of these phenomena in the period from...
  • Publication
    Long-Term Trends and Gleissberg Cycles in Aurora Borealis Records (1600 - 2015)
    The long-term spatial and temporal variation of aurora borealis events from 1600 to the present were studied using catalogues and other records of these...
  • Publication
    Long-term Variation of Solar Activity by a Dynamo Based on Magnetic Flux Tubes
    We show that cyclic activity and Maunder-type grand minima can be explained by a dynamo driven by the instability of magnetic flux tubes in the overshoot layer...
  • Talk
    Magnetic bright points in the quiet Sun
    We present a visual determination of the number of bright points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic...
  • Publication
    Modeling of integrated sunlight velocity measurements: The effect of surface darkening by magnetic fields
    It has been known since the work by Claverie et al. (1982) that integrated-sunlight velocities measured with the resonance scattering technique show variations...
  • Talk
    Mysteries of the magnetic Sun
    The Sun presents us with many unsolved mysteries. In this talk I discuss three of them that have intrigued me for the last 50 years. Solar flares are the most...
  • Publication
    New windows to the universe; Proceedings of the Eleventh European Regional Astronomy Meeting, Universidad de la Laguna, Spain, July 3-8, 1989. Part II
    Recent observational and theoretical investigations of the sun and sunlike stars and of galactic structure and evolution are discussed in reviews and reports...
  • Publication
    Nonlinear time-evolution of kink-unstable magnetic flux tubes in the convective zone of the sun
    The nonlinear development of the kink instability in a horizontal magnetic flux tube with a field strength exceeding the equipartition value lying initially in...