相关论文: On the origin of reverse polarity patches found by…
High resolution spectropolarimetric observations by Hinode reveal the existence of supersonic downflows at the umbra-penumbra boundary of 3 sunspots that was recently reported by Louis et al. (2010). These downflows are observed to be…
Based on the Meso-Structured Magnetic Atmosphere (MESMA) approximation, recently introduced by Carroll & Kopf (2007), we present first results of an inversion of spectropolarimetric observations obtained from solar internetwork regions. To…
Recent progress in theoretical modeling of a sunspot is reviewed. The observed properties of umbral dots are well reproduced by realistic simulations of magnetoconvection in a vertical, monolithic magnetic field. To understand the penumbra,…
We study the magnetohydrostatic equilibrium of magnetic flux tubes with circular cross sections embedded in a magnetic surrounding atmosphere. We solve the static momentum equation in 2.5D to obtain the thermodynamics that are consistent…
The Solar Optical Telescope onboard Hinode revealed the fine-scale structure of the Evershed flow and its relation to the filamentary structures of the sunspot penumbra. The Evershed flow is confined in narrow channels with nearly…
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 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…
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…
High-resolution observations of sunspots have revealed the existence of dark cores inside the bright filaments of the penumbra. Here we present the stationary solution of the heat transfer equation in a stratified penumbra consisting of…
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…
Context : Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields. Aims : We study the formation of a penumbra in a decaying sunspot and compare its…
We present numerical 2D magnetostatic models for sunspot penumbrae consisting of radially aligned field-free gaps in a potential magnetic field, as proposed by Spruit and Scharmer (2006). The shape of the gaps and the field configurations…
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.…
Observations of the sun suggest that solar activities systematically create north-south hemispheric asymmetries. For instance, the hemisphere in which the sunspot activity is more active tends to switch after the early half of each solar…
We study 7530 sunspot umbrae and pores measured by the Hinode Spectropolarimeter (SP) between November 2006 and November 2012. We primarily seek confirmation of the long term secular decrease in the mean magnetic field strength of sunspot…
The formation of unusually shaped Stokes V profiles of the Fe I 630.2 nm line in the solar photosphere are investigated. The results of numerical 2-D MHD simulation of solar magnetogranulation are used for this. In their properties, the…
We report the discovery of supersonic downflows in a sunspot light bridge using measurements taken with the spectropolarimeter on board the Hinode satellite. The downflows occur in small patches close to regions where the vector magnetic…
We investigate the thermal and kinematic configuration of a sunspot penumbra using very high spectral and spatial resolution intensity profiles of the non-magnetic Fe I 557.6 nm line. The dataset was acquired with the 2D solar spectrometer…
The Hinode satellite opens a new era to the sunspots research, because of its high spatial resolution and temporal stability. Fine scale structures in sunspots, called umbral dots (UDs), have become one of the hottest topics in terms of the…
In the past two decades, the complex nature of sunspots has been disclosed with high-resolution observations. One of the most important findings is the "uncombed" penumbral structure, where a more horizontal magnetic component carrying most…