Related papers: Peripheral downflows in sunspot penumbrae
Time series of high-resolution images of the complex active region NOAA 10786 are studied. The observations were performed in G-band (430.5 nm) and in the nearby continuum (463.3 nm), on July 9, 2005 at the Swedish 1-meter Solar Telecope…
We present the results obtained by analyzing high spatial and spectral resolution data of the solar photosphere acquired by the CRisp Imaging SpectroPolarimeter at the Swedish Solar Telescope on 6 August 2011, relevant to a large sunspot…
Numerical simulations have by now revealed that the fine scale structure of the penumbra in general and the Evershed effect in particular is due to overturning convection, mainly confined to gaps with strongly reduced magnetic field…
The generation of magnetic flux in the solar interior and its transport to the outer solar atmosphere will be in the focus of solar physics research for the next decades. One key-ingredient is the process of magnetic flux emergence into the…
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…
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 present spectropolarimetric measurements of dark-cored penumbral filaments taken with Hinode at a resolution of 0.3". Our observations demonstrate that dark-cored filaments are more prominent in polarized light than in continuum…
Solar pores are active regions with large magnetic field strengths and apparent simple magnetic configurations. Their properties resemble the ones found for the sunspot umbra although pores do not show penumbra. Therefore, solar pores…
Sunspots are prominent manifestations of the solar cycle and provide key constraints for understanding its operation. Also, knowing internal structure of sunspots allows us to gain insights on the energy transport in strong magnetic fields…
The penumbra is ideally suited to challenge our understanding of magnetohydrodynamics. The energy transport takes place as magnetoconvection in inclined magnetic fields under the effect of strong radiative cooling at the surface. The…
The satellite Hinode has recently revealed penumbral structures with a magnetic polarity opposite to the main sunspot polarity. They may be a direct confirmation of magnetic field lines and mass flows returning to the solar interior…
We present the observations of penumbra like features (PLFs) near a polarity inversion line (PIL) of flaring region. The PIL is located at the moat boundary of active region (NOAA 10960). The PLFs appear similar to sunspot penumbrae in…
We observed small scale magnetic flux emergence in a sunspot moat region by the Solar Optical Telescope (SOT) aboard the Hinode satellite. We analyzed filtergram images observed in the wavelengths of Fe 6302 angstrom, G-band and Ca II H. In…
A light bridge is a prominent structure commonly observed within a sunspot. Its presence usually triggers a wealth of dynamics in a sunspot, and has a lasting impact on sunspot evolution. However, the fundamental structure of light bridges…
We present a realistic numerical model of sunspot and active region formation based on the emergence of flux bundles generated in a solar convective dynamo. To this end we use the magnetic and velocity fields in a horizontal layer near the…
Sunspots harboring umbrae of both magnetic polarities within a common penumbra (delta-spots) are often but not always related to flares. We present first near-infrared (NIR) observations (Fe I 1078.3 nm and Si I 1078.6 nm spectra) obtained…
We compare the properties of kG magnetic structures in the solar network and in active region plage at high spatial resolution. Our analysis used six SP scans of the solar disc centre aboard Hinode SOT and inverted the obtained spectra of…
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…
The line profile asymmetry defining the Evershed effect in sunspot penumbrae, disappears abruptly at the outer sunspot boundary over a horizontal distance of less than 500 km immediately at the outermost ends of the dark penumbral continuum…
We investigated the role of photospheric plasma motions in the formation and evolution of polar magnetic patches using time-sequence observations with high spatial resolution. The observations were obtained with the spectropolarimeter on…