Related papers: Propagating wave in active region-loops, located o…
Line-of-sight magnetograms for 217 active regions (ARs) of different flare rate observed at the solar disk center from January 1997 until December 2006 are utilized to study the turbulence regime and its relationship to the flare…
We characterize waves in small magnetic elements and investigate their propagation in the lower solar atmosphere from observations at high spatial and temporal resolution. We use the wavelet transform to analyze oscillations of both…
Twisted coronal loops in the solar atmosphere may become kink-unstable when their magnetic field lines are sufficiently twisted. This instability can trigger magnetic reconnection, leading to the emission of electromagnetic radiation, which…
Quiescent filaments appear as absorption features on the solar disk when observed in chromospheric lines and at continuum wavelengths in the millimeter (mm) range. Active region (AR) filaments are their small-scale, low-altitude analogues,…
Winking (oscillating) filaments have been observed for many years. However, observations of successive winking filaments in one event have not been reported yet. In this paper, we present the observations of a chain of winking filaments and…
Height series of H${\alpha}$ spectra in solar limb spicules obtained with the 53 cm coronagraph of the Abastumani Astrophysical Observatory are analyzed. Each height series covered 8 different heights beginning at 3800 km above the…
In the present paper, we use Si IV 1393.755 \AA\ spectral line observed by the Interface Region Imaging Spectrograph (IRIS) in the quiet-Sun to determine physical nature of the solar transition region (TR) oscillations. We analyze the…
We have made high-resolution, high-sensitivity dynamic spectra of a sample of strong pulsars at 430 MHz with the Arecibo radiotelescope. For 4 pulsars we find faint but sharply delineated features in the secondary spectra. These are…
We analyze the high-resolution observations from the 1.6m telescope at Big Bear Solar Observatory that cover an active region filament. Counter-streaming motions are clearly observed in the filament. The northern end of the…
We present a statistical study of 130 solar flares (B to X class) that lack soft X-ray quasi-periodic pulsations and show no kink oscillations of nearby coronal loops visible in SDO/AIA 171~\AA~images. The aim is to investigate whether…
The solar active region NOAA 11719 produced a large two-ribbon flare on 11 April 2013. We have investigated the sudden variations in the photospheric magnetic fields in this active region during the flare employing the magnetograms obtained…
Recent observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode have shown that low density areas on the periphery of active regions are characterized by strong blue-shifts at 1 MK. These Doppler shifts have been…
On April 18, 2014 (SOL2014-04-18T13:03) an M-class flare was observed by IRIS. The associated flare ribbon contained a quasi-periodic sawtooth pattern that was observed to propagate along the ribbon, perpendicular to the IRIS spectral slit,…
Coronal oscillations offer insight into energy transport and driving in the solar atmosphere. Knowing its polarisation state helps constrain a wave's displacement and velocity amplitude, improving estimates of wave energy flux and…
We report the detection of oscillatory phenomena associated with a large bright-point group that is 430,000 square kilometers in area and located near the solar disk center. Wavelet analysis reveals full-width half-maximum oscillations with…
Nanoflares are regarded as one of the major mechanisms of magnetic energy release and coronal heating in the solar outer atmosphere. We conduct a statistical study on the response of the chromosphere and transition region to nanoflares, as…
We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magneto-hydrodynamic code, respectively. Each dataset demonstrates a…
We report on the spectral features of the Si IV 1402.77 \AA, C II 1334.53 \AA, and Mg II h or k lines, formed in the layers from the transition region to the chromosphere, in three two-ribbon flares (with X-, M-, and C-class) observed with…
The Interface Region Imaging Spectrometer (IRIS) is the first solar instrument to observe $\sim 10$ MK plasma at subarcsecond spatial resolution through imaging spectroscopy of the Fe XXI $\lambda$1354.1 forbidden line. IRIS observations of…
Torsional Alfv\'en waves do not produce any intensity variation and are, therefore, challenging to observe with imaging instruments. Previously, Alfv\'en wave observations were reported throughout all the layers of the solar atmosphere…