Related papers: Super Penumbral Chromospheric Flare
In this paper, we present a multi-wavelength analysis of two X-class solar eruptive flares of classes X2.2 and X9.3 that occurred in the sigmoidal active region NOAA 12673 on 2017 September 6, by combining observations of Atmospheric…
Experiments with interacting high-velocity flows of laser plasma can help answer the fundamental questions in plasma physics and improve the understanding of the mechanisms behind astrophysical phenomena, such as formation of collisionless…
As one of the most common features in the solar atmosphere, filaments are significant not only in the solar physics but also in the stellar and laboratory plasma physics. With the New Vacuum Solar Telescope and the Solar Dynamics…
It is shown that a generalized magneto-Bernoulli mechanism can effectively generate high velocity flows in the Solar chromosphere by transforming the plasma pressure energy into kinetic energy. It is found that at reasonable heights and for…
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…
We use spectropolarimetric observations of the Ca II 8542~\AA\ line, taken from the Swedish 1-m Solar Telescope (SST), in an attempt to recover dynamic activity in a micro-flaring region near a sunspot via inversions. These inversions show…
A density structure within the magnetic cloud of an interplanetary coronal mass ejection impacted Earth and caused significant perturbations in plasma boundaries. We describe the effects of this structure on the magnetosheath plasma…
We report on observation of the unusual kind of solar microflares, presumably associated with the so-called "topological trigger" of magnetic reconnection, which was theoretically suggested long time ago by Gorbachev et al. (Sov. Ast. 1988,…
Observations of interstellar scintillations at radio wavelengths reveal a Kolmogorov-like scaling of the electron density spectrum with a spectral slope of -5/3 over six decades in wavenumber space. A similar turbulent density spectrum in…
We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…
Magnetic flux emergence from the convection zone into the photosphere and beyond is a critical component of the behaviour of large-scale solar magnetism. Flux rarely emerges amid field-free areas at the surface, but when it does, the…
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…
Doppler shifts in chromospheric and transition-region lines during solar flares are often interpreted as chromospheric condensation or evaporation. However, alternative sources of Doppler-shifted emission have been suggested, such as…
We analyzed high-cadence sit-and-stare observations acquired with the Hinode/EIS spectrometer and HXR measurements acquired with RHESSI during an M-class flare. During the flare impulsive phase, we observe no significant flows in the cooler…
Magnetic fields emerging from the Sun's interior carry information about physical processes of magnetic field generation and transport in the convection zone. Soon after appearance on the solar surface the magnetic flux gets concentrated in…
We present the results of a detailed analysis of multi-wavelength observations of a very impulsive solar flare 1B/M6.7, which occurred on 10 March, 2001 in NOAA AR 9368 (N27 W42). The observations show that the flare is very impulsive with…
Solar flares are one of the main forces behind space weather events. However the mechanism that drives such energetic phenomena is not fully understood. The standard eruptive flare model predicts that magnetic reconnection occurs high in…
Oscillations are ubiquitous in sunspots and the associated higher atmospheres. However, it is still unclear whether these oscillations are driven by the external acoustic waves (p-modes) or generated by the internal magnetoconvection. To…
In space plasmas kinetic instabilities are driven by the beaming (drifting) components and/or the temperature anisotropy of charged particles. The heat-flux instabilities are known in the literature as electromagnetic modes destabilized by…
High resolution spectra from the Hinode EUV Imaging Spectrometer (EIS) have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km/s. These asymmetries could…