Related papers: All Coronal Loops are the Same: Evidence to the Co…
Radiative losses play a critical role in the cooling of plasmas. When chromospheric plasma is sufficiently heated, it can flow into coronal loops which subsequently cool down due to radiation. From observations, we infer that this cooling…
Helmet streamers are a prominent manifestation of magnetic structures with current sheets in the solar corona. These large-scale structures are regions with high plasma density, overlying active regions and filament channels. We investigate…
We present an in-depth characterization of the polarimetric channel of the Large-Angle Spectrometric COronagraph/LASCO-C3 onboard SOHO. The polarimetric analysis of the white-light images makes use of polarized sequences composed of three…
The physical processes causing energy exchange between the Sun's hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that…
We study the signatures of different coronal heating regimes on the differential emission measure (DEM) of multi-stranded coronal loops by means of hydrodynamic simulations. We consider heating either uniformly distributed along the loops…
We examine the hypothesis that multipolar magnetic fields advected by photospheric granules can contribute heating to the active chromosphere and corona. On 28 September 2020 the GRIS and HiFI+ instruments at the GREGOR telescope obtained…
Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated…
Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite…
Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…
In a recent work Grappin et al. [1] have shown that low- frequency movements can be transmitted from one footpoint to the other along a magnetic loop, thus mimicking a friction effect of the corona on the photosphere, and invalidating the…
Rapidly decaying long-period oscillations often occur in hot coronal loops of active regions associated with small (or micro-) flares. This kind of wave activity was first discovered with the SOHO/SUMER spectrometer from Doppler velocity…
A technique is described for measuring electrical currents in the solar corona. It uses radioastronomical polarization measurements of a spatially-extended radio source viewed through the corona. The observations yield the difference in the…
We study plasma flows along selected coronal loops in NOAA Active Region 10926, observed on 3 December 2006 with Hinode's EUV Imaging Spectrograph (EIS). From the shape of the loops traced on intensity images and the Doppler shifts measured…
We report on the discovery of periodic coronal rain in an off-limb sequence of {\it Solar Dynamics Observatory}/Atmospheric Imaging Assembly images. The showers are co-spatial and in phase with periodic (6.6~hr) intensity pulsations of…
In order to study the solar corona during eclipses, a new telescope was constructed. Three coronal images were obtained simultaneously from one objective of the telescope as the coronal radiation passed through three polarisers (whose…
It is generally accepted that densities of quiet sun and active region plasma are sufficiently low to justify the optically thin approximation, and it is commonly used in the analysis of line emissions from plasma in the solar corona.…
We report on the plasma properties of small-scale transient events identified in the quiet Sun, coronal holes and their boundaries. We use spectroscopic co-observations from SUMER/SoHO and EIS/Hinode combined with high cadence imaging data…
To understand the nonlinear dynamics of the Parker scenario for coronal heating, long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out. A loop is modeled as a box extended along the…
As a part of a study of the cause of solar coronal heating, we searched for high-frequency (~1 Hz) intensity oscillations in coronal loops in the [Fe XIV] coronal green line. We summarize results from observations made at the 11 August 1999…
The effect of temperature inhomogeneity on the periods, their ratios (fundamental vs. first overtone), and the damping times of the standing slow modes in gravitationally stratified solar coronal loops are studied. The effects of optically…