Related papers: The uncombed penumbra
(adapted)Considering recent observations challenging the traditional magnetar model, we explore the wind braking of magnetars. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from…
We applied automatic identification of sunspot umbrae and penumbrae to daily observations from the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) to study their magnetic flux (B) and area (A). The results…
We investigate, by numerical simulations, the photometric signature of magnetic flux tubes in the solar photosphere. We show that the observed contrast profiles are determined not only by the physical properties of the tube and its…
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. To this extent, we inverted data taken with the spectropolarimeter (SP) aboard Hinode…
The magnetic field in the local interstellar medium does not follow the large-scale Galactic magnetic field. The local magnetic field has probably been distorted by the Local Bubble, a cavity of hot ionized gas extending all around the Sun…
While amongst the most luminous objects in the universe, many details regarding the inner structure of quasars remain unknown. One such area is the mechanism promoting increased polarisation in the broad absorption line troughs of certain…
Solar flares - which are the most prominent manifestation of the solar activity - typically manifest themselves as a single or a set of luminous arcs (magnetic flux tubes) rooted in regions of opposite polarity in the photosphere. However,…
Formation of the H$\beta$ $\lambda$4861.34 \AA{} line is an important topic related to the diagnosis of the basic configuration of magnetic fields in the solar and stellar chromospheres. Specifically, broadening of the H$\beta$…
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 report the spontaneous formation of bipolar magnetic structures in direct numerical simulations of stratified forced turbulence with an outer coronal envelope. The turbulence is forced with transverse random waves only in the lower…
We discuss penumbral fine structure in a small part of a pore, observed with the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope (SST), close to its diffraction limit of 0.16 arcsec. Milne-Eddington inversions applied to…
The formation of sunspots requires the concentration of magnetic flux near the surface. The negative magnetic pressure instability (NEMPI) might be a possible mechanism for accomplishing this, but it has mainly been studied in simple…
We present the results of high resolution co-temporal and co-spatial photospheric and chromospheric observations of sunspot penumbral intrusions. The data was taken with the Swedish Solar Telescope (SST) on the Canary Islands. Time series…
The anomalous heating of the solar upper atmosphere is one of the eight key problems in modern astronomy. Moreover, the stratification of the solar atmosphere is an outstanding key-problem in solar physics. In this study, a hot…
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…
The new generation of ground-based, large-aperture solar telescopes promises to significantly increase our capabilities to understand the many basic phenomena taking place in the Sun at all atmospheric layers and how they relate to each…
A typical sunspot, as seen in white-light intensity images, has a two part structure: a dark umbra and a lighter penumbra. Such distinction primarily arises due to the different orientations of magnetic fields in these two regions. In this…
We observed an elongated filamentary bright structure inside the umbra of the big sunspot in active region NOAA 12529, which differs from the light bridges usually observed in sunspots for its morphology, magnetic configuration, and…
A magnetic model is proposed for describing the incommensurate I phase of spin-Peierls systems. Based on the harmonicity of the lattice distortion, its main ingredient is that the distortion of the lattice adjusts to the average…
This work deals with the presence of thick branes in a model with two source scalar fields that interact with one another in a very specific way. The model is new, capable of generating kinklike configurations that engender important…