Related papers: Identifying typical Mg II flare spectra using mach…
Of all the activity observed on the Sun, two of the most energetic events are flares and Coronal Mass Ejections (CMEs). Usually, solar active regions that produce large flares will also produce a CME, but this is not always true (Yashiro et…
The asymmetries observed in the line profiles of solar flares can provide important diagnostics of the properties and dynamics of the flaring atmosphere. In this paper the evolution of the Halpha and Ca II 8542 {\AA} lines are studied using…
In this paper, we present for the first time a comprehensive statistical study between type II radio bursts from the metric (m) to the dekameric-hectometric (DH) domain and their associated solar and space weather (SW) phenomena, namely,…
Solar flares are intense eruptive events caused by the rapid release of magnetic energy, often impacting Earth's space environment through electromagnetic radiation and high-energy particles. Accurate flare prediction is critical for space…
The presence of flare related acoustic emission (sunquakes) in some flares represents a severe challenge to our current understanding of flare energy transport processes. We present a comparison of new spectral observations from Hinode's…
We study the M1.9 class solar flare SOL2015-09-27T10:40 UT using high-resolution full-Stokes imaging spectropolarimetry of the Ca ii 8542 {\AA} line obtained with the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope.…
We present a statistical study of chromospheric evaporation in solar flares using simultaneous observations by the RHESSI X-ray telescope and the IRIS UV spectrograph. The results are compared with radiation hydrodynamic flare models from…
The precise physical process that triggers solar flares is not currently understood. Here we attempt to capture the signature of this mechanism in solar image data of various wavelengths and use these signatures to predict flaring activity.…
The Sun's chromosphere is a critical region to understand when considering energy and mass deposition into the transition region and corona, but many of the smaller, faster events which transport a portion of this mass and energy are still…
Although the h and k lines of MgII are expected to be of great interest for probing the upper solar chromosphere, relatively little is known about their polarization properties which encode the information on the magnetic field. Here we…
We present results of non-LTE modeling of H-alpha 6563 A and Mg II k&h 2796 A and 2803 A lines. This modeling is important for interpretation of coordinated observations from the recently launched NASA's IRIS mission and from the New Solar…
CHROMIS, a new imaging spectrometer at the Swedish 1-m Solar Telescope (SST), can observe the chromosphere in the H and K lines of Ca II at high spatial and spectral resolution. Accurate modeling as well as an understanding of the formation…
Solar flare prediction plays an important role in understanding and forecasting space weather. The main goal of the Helioseismic and Magnetic Imager (HMI), one of the instruments on NASA's Solar Dynamics Observatory, is to study the origin…
With observations of IRIS, we study chromospheric heating and evaporation during an M1.6 flare SOL2015-03-12T11:50. At the flare ribbons, the Mg II 2791.59 line shows quasi-periodic short-duration red-wing enhancement, which is likely…
We present results from an empirical study of the Mg II h & k emission lines of selected Mira variable stars, using spectra from the International Ultraviolet Explorer (IUE). The stars all exhibit similar Mg II behavior during the course of…
Because of the complex physics that governs the formation of chromospheric lines, interpretation of solar chromospheric observations is difficult. The origin and characteristics of many chromospheric features are, because of this,…
Context: Flare kernels brighten simultaneously in all SDO/AIA channels making it difficult to determine their temperature structure. IRIS is able to spectrally resolve Fe xxi emission from cold chromospheric brightenings, so can be used to…
The composition of plasma in the solar corona is characterised by the First Ionisation Potential (FIP) bias, and is thought to be the result of a ponderomotive force acting in the chromosphere to separate ionised from neutral plasma.…
Machine learning can provide powerful tools to detect patterns in multi-dimensional parameter space. We use K-means -a simple yet powerful unsupervised clustering algorithm which picks out structure in unlabeled data- to study a sample of…
Imaging observations of the solar lower atmosphere by the Atmosphere Imaging Assembly (AIA) have been mostly used as the context, and their quantitative information has been much less explored. The chromosphere responds rapidly to energy…