Related papers: The Evershed effect observed with 0.2 arsec angula…
Recent spectro-polarimetric observations of a sunspot showed the formation of bipolar magnetic patches in the mid penumbra and their propagation toward the outer penumbral boundary. The observations were interpreted as being caused by…
We present a simple 'shift-and-add' based improvement in the angular resolution of single electron backscatter diffraction (EBSD) patterns. Sub-pixel image registration is used to measure the (sub-pixel) difference in projection parameters…
We analyze several unusual filamentary structures, which appeared in the umbra of one of the sunspots in AR 11302. They do not resemble typical light bridges, neither in morphology, nor in evolution. We analyze data from SDO/HMI to…
The analyses of sunspot observations revealed a fundamental magnetic property of the umbral boundary, the invariance of the vertical component of the magnetic field. We aim to analyse the magnetic properties of the umbra-penumbra boundary…
Spectropolarimetric observations used to infer the solar magnetic fields are obtained with a limited spatial resolution. The effects of this limited resolution on the inference of the open flux over the observed region have not been…
Sunspots are concentrations of magnetic field on the visible solar surface that strongly affect the convective energy transport in their interior and surroundings. The filamentary outer regions (penumbrae) of sunspots show systematic radial…
The sunspot penumbra is a transition zone between the strong vertical magnetic field area (sunspot umbra) and the quiet Sun. The penumbra has a fine filamentary structure that is characterized by magnetic field lines inclined toward the…
To deepen the analysis of the photometric properties of the umbra of a sunspot, we study proper motions of small features such as umbral dots (UDs) inside a single sunspot observed by the Solar Optical Telescope of Hinode close to the disk…
We perform NLTE inversions in a large set of umbral flashes, including the dark fibrils visible within them, and in the quiescent umbra by using the inversion code NICOLE on a set of full Stokes high-resolution Ca II 8542 A observations of…
Subject of this paper are intrinsic ellipticity correlations between galaxies, their statistical properties, their observability with future surveys and their interference with weak gravitational lensing measurements. Using an angular…
The sunspot penumbra comprises numerous thin, radially elongated filaments that are central for heat transport within the penumbra, but whose structure is still not clear. To investigate the fine-scale structure of these filaments, we…
Aims: The primary objective of this study is to search for and identify wave modes within a sunspot penumbra. Methods: Infrared spectropolarimetric time series data are inverted using a model comprising two atmospheric components in each…
Sunspot penumbrae show a fine structure in continuum intensity that displays considerable dynamics. The magnetic field, in contrast, although also highly structured, has appeared to be relatively static. Here we report the discovery of…
Future lensing surveys will be nearly full-sky and reach an unprecedented depth, probing scales closer and closer to the Hubble radius. This motivates the study of the cosmic shear beyond the small-angle approximation and including general…
The decay of sunspot plays a key role in magnetic flux transportation in solar active regions (ARs). To better understand the physical mechanism of the entire decay process of a sunspot, an {\alpha}-configuration sunspot in AR NOAA 12411…
It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying…
We study the dynamics of plasma along the legs of an arch filament system (AFS) from the chromosphere to the photosphere, observed with high-cadence spectroscopic data from two ground-based solar telescopes: the GREGOR telescope (Tenerife)…
The magnetic and velocity fields in sunspots are highly structured on small spatial scales which are encoded in the Stokes profiles. Our aim is to identify Stokes profiles in a sunspot which exhibit spectral characteristics that deviate…
We determine the entire electrical current density vector in a geometrical 3D volume of the inner penumbra of a sunspot from an inversion of spectropolarimetric data obtained with Hinode/SP. Significant currents are seen to wrap around the…
The influence of the convective structure of the solar photosphere on the shifts of spectral lines of iron was studied. Line profiles in the visible and infrared spectrum were synthesized with the use of 2-D time-dependent hydrodynamic…