相关论文: Orphan penumbrae: Submerging horizontal fields

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…

Aims: We search for penumbral magnetic fields of opposite polarity and for their correspondence with downflows. Methods: We used spectropolarimetric HINODE data of a spot very close to disk center to suppress the horizontal velocity…

As observed in spectral lines originating from the chromosphere, transition region, and low corona, active regions are surrounded by an extensive "circumfacular" area which is darker than the quiet Sun. We examine the properties of these…

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…

The conjecture that energy transport in sunspot penumbrae occurs through convection by an interchange of magnetic flux tubes is used in order to construct a magnetostatic model for a deep penumbra which is part of a global sunspot model.…

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…

Context. The bright heads of penumbral filaments, penumbral grains (PGs), are manifestations of hot plasma flows rising to the surface. They are observed to move horizontally toward the sunspot umbra or away from it. Recent analyses of…

Proper motions in a sunspot group with a delta-configuration and close to the solar disc center have been studied by employing local correlation tracking techniques. The analysis is based on more than one hour time series of G-band images.…

Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable…

Inversions of spectropolarimetric observations of penumbral filaments deliver the stratification of different physical quantities in an optical depth scale. However, without establishing a geometrical height scale their three-dimensional…

Polar faculae are bright features that can be detected in solar limb observations and they are related to magnetic field concentrations. Although there is a large number of works studying them, some questions about their nature as their…

We study the velocity structure of penumbral filaments in the deep photosphere to obtain direct evidence for the convective nature of sunspot penumbrae. A sunspot was observed at high spatial resolution with the 1-m Swedish Solar Telescope…

We study the presence of reversed polarity magnetic flux in sunspot penumbra. We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based…

High resolution imaging observation of a sunspot umbra was done with Hinode Solar Optical Telescope (SOT). Filtergrams in wavelengths of blue and green continuum were taken during three consecutive days. The umbra consisted of a dark core…

Filaments are considered to be basic structures and molecular clouds consist of filaments. Filaments are often observed as extending in the direction perpendicular to the interstellar magnetic field. The structure of filaments has been…

Whereas penumbral models during the last 15 years have been successful in explaining Evershed flows and magnetic field inclination variations in terms of flux tubes, the lack of contact between these models and a convective process needed…

MHD simulations of sunspots have successfully reproduced many aspects of sunspot fine structure as consequence of magneto convection in inclined magnetic field. We study how global sunspot properties and penumbral fine structure depend on…

We report on new spectro-polarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at…

Recent numerical simulations and observations of sunspots show a significant amount of opposite polarity magnetic field within the sunspot penumbra. Most of the opposite polarity field is associated with convective downflows. We present an…

We present a study of wave processes in the sunspot region NOAA 12670 on 2017 August 10 observed by the Goode Solar Telescope in the TiO 7057 A and Ha 6563 A spectral lines. To study the distribution of power oscillations and their…