Three-dimensional structure of a sunspot light bridge
Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar...
Tracing p-mode Waves from the Photosphere to the Corona in Active Regions
Atmosphere above sunspots is abundant with different types of waves. Among these waves are running penumbral waves in the chromosphere, quasi-periodic...
Results from a numerical and analytical investigation of the solution of a nonlinear axisymmetric diffusion equation for the magnetic field are presented for...
Twist, Writhe, and Helicity in the Inner Penumbra of a Sunspot
The aim of this work is the determination of the twist, writhe, and self-magnetic helicity of penumbral filaments located in an inner sunspot penumbra. For this...
The magnetic and kinematic configuration of sunspot penumbrae is investigated by performing an inversion of the Stokes profiles of three infrared lines at 1565...
Umbral dots - A case of penetrative convection between sunspot fragments
A study of the observations made on the development and, in some cases, even the decay of 15 large active regions is presented. It is shown that the mature...
Unusual Stokes V profiles during flaring activity of a delta sunspot
Aims: We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808. The region was recorded with the Vector-Spectromagnetograph...
Upper chromospheric magnetic field of a sunspot penumbra: observations of fine structure
Aims: The fine-structure of the magnetic field in a sunspot penumbra in the upper chromosphere is to be explored and compared to that in the photosphere...
Variation in sunspot properties between 1999 and 2011 as observed with the Tenerife Infrared Polarimeter
Aims: We study the variation in the magnetic field strength and the umbral intensity of sunspots during the declining phase of the solar cycle No. 23 and in the...