Related papers: Temporal Evolution of the Inverse Evershed Flow
We determined the direction and strength of the photospheric and lower chromospheric magnetic field in the umbra and penumbra of a sunspot from inversions of spectropolarimetric observations of photospheric lines at 617\,nm and 1565\,nm,…
We present the properties of the inverse Evershed flow (IEF) based on the center-to-limb variation of the plasma speed and loop geometry of chromospheric superpenumbral fibrils in eleven sunspots that were located at a wide range of…
The inverse Evershed flow (IEF) is a mass motion towards sunspots at chromospheric heights. We combined high-resolution observations of NOAA 12418 from the Dunn Solar Telescope and vector magnetic field measurements from the Helioseismic…
In addition to the Evershed flow directed from the umbra towards the outer boundary of the sunspot, under special circumstances, a counter Evershed flow (CEF) in the opposite direction also occurs. We aim to characterize the proper motions…
There have been a few reports in the literature of counter-Evershed flows observed in well developed sunspot penumbrae, i.e. flows directed towards the umbra along penumbral filaments. Here we investigate the driving forces of such…
[Abridged] The magnetic and kinematic properties of the photospheric Evershed flow are relatively well known, but we are still far from a complete understanding of its nature. The evolution of the flow with time, which is mainly due to…
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…
Context. The presence of the moat flow around sunspots is intimately linked to the mere existence of sunspots. Aims. We characterize the moat flow (MF) and Evershed flow (EF) in sunspots to enhance our knowledge of sunspot structures and…
One of the main characteristics of the penumbra of sunspots is the radially outward-directed Evershed flow. Only recently have penumbral regions been reported with similar characteristics to normal penumbral filaments, but with an opposite…
The motion of an individual magnetic flux tube inside the penumbra of a sunspot is studied numerically. Here, we present preliminary results. The thin flux tube approximation together with a simplified radiative heat exchange with the…
The sunspot penumbra is usually observed in the photosphere and it is of particular interest for its magneto-convection which seems to transport the heat from the top of the convection zone into the solar atmosphere. It is well known that…
We studied the variations of line-of-sight photospheric plasma flows during the formation phase of the penumbra around a pore in Active Region NOAA 11490. We used a high spatial, spectral, and temporal resolution data set acquired by the…
The Evershed flow is a systematic motion of gas that occurs in the penumbra of all sunspots. Discovered in 1909, it still lacks a satisfactory explanation. We know that the flow is magnetized, often supersonic, and that it shows conspicuous…
The relation between the Evershed flow and moving magnetic features (MMFs) is studied using high-cadence, simultaneous spectropolarimetric measurements of a sunspot in visible (630.2 nm) and near-infrared (1565 nm) lines. Doppler…
Assuming that the interchange convection of magnetic flux elements is the physical cause for the existence of filamentary penumbrae in sunspots, we investigate the behavior of an individual fibril embedded in the deep penumbra. The fibril…
We observed a C-class flare at the outer boundary of the super-penumbra of a sunspot. The flare was triggered by an emerging magnetic bipolar region that was obliquely oriented with respect to the super-penumbral fibrils. The flare started…
Context. The Evershed effect, a nearly horizontal outflow of material seen in the penumbrae of sunspots in the photospheric layers, is a common characteristic of well-developed penumbrae, but is still not well understood. Even less is known…
We investigate the temporal relation between the Evershed flow, dot-like bright features (penumbral grain), the complex magnetic field structure, and dark lanes (dark core) along bright filaments in a sunspot penumbra. We use a time series…
We investigate the fine structure of the sunspot penumbra by means of a model that allows for a flux tube in horizontal pressure balance with the magnetic background atmosphere in which it is embedded. We apply this model to…
The photospheric Evershed flow is normally oriented radially outward, yet sometimes opposite velocities are observed not only in the chromosphere but also in the photospheric layers of the penumbra. We study the velocity field in a special…