Search Publications
First Detection of Plasmoids from Breakout Reconnection on the Sun
Antiochos, Spiro K.; Kumar, Pankaj; DeVore, C. Richard +2 more
Transient collimated plasma ejections (jets) occur frequently throughout the solar corona, in active regions, quiet Sun, and coronal holes. Although magnetic reconnection is generally agreed to be the mechanism of energy release in jets, the factors that dictate the location and rate of reconnection remain unclear. Our previous studies demonstrate…
Properties of Slow Magnetoacoustic Oscillations of Solar Coronal Loops by Multi-instrumental Observations
Moon, Y. -J.; Nakariakov, V. M.; Kumar, P. +3 more
Rapidly decaying oscillations of the thermal emission detected in the decay phase of solar and stellar flares are usually interpreted as standing or sloshing (reflecting) slow magnetoacoustic oscillations. We determine the scalings of the oscillation periods, damping times, and amplitudes with the temperature, considering both standing and sloshin…
Record-breaking Coronal Magnetic Field in Solar Active Region 12673
Fleishman, Gregory D.; Anfinogentov, Sergey A.; Stupishin, Alexey G. +1 more
The strongest magnetic fields on the Sun are routinely detected at dark sunspots. The magnitude of the field is typically about 3000 G, with only a few exceptions that reported the magnetic field in excess of 5000 G. Given that the magnetic field decreases with height in the solar atmosphere, no coronal magnetic field above ∼2000 G has ever been r…
Transient Inverse-FIP Plasma Composition Evolution within a Solar Flare
Long, David M.; Matthews, Sarah A.; Brooks, David H. +9 more
Understanding elemental abundance variations in the solar corona provides an insight into how matter and energy flow from the chromosphere into the heliosphere. Observed variations depend on the first ionization potential (FIP) of the main elements of the Sun’s atmosphere. High-FIP elements (>10 eV) maintain photospheric abundances in the coron…
Spectroscopy and Differential Emission Measure Diagnostics of a Coronal Dimming Associated with a Fast Halo CME
Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +2 more
We study the coronal dimming caused by the fast halo CME (deprojected speed v = 1250 km s-1) associated with the C3.7 two-ribbon flare on 2012 September 27, using Hinode/EIS spectroscopy and Solar Dynamics Observatory (SDO)/AIA Differential Emission Measure (DEM) analysis. The event reveals bipolar core dimmings encompassed by hook-shap…
Multi-component Decomposition of Astronomical Spectra by Compressed Sensing
Winebarger, Amy R.; Antolin, Patrick; Testa, Paola +9 more
The signal measured by an astronomical spectrometer may be due to radiation from a multi-component mixture of plasmas with a range of physical properties (e.g., temperature, Doppler velocity). Confusion between multiple components may be exacerbated if the spectrometer sensor is illuminated by overlapping spectra dispersed from different slits, wi…
Exploring Plasma Heating in the Current Sheet Region in a Three-dimensional Coronal Mass Ejection Simulation
Reeves, Katharine K.; Mikić, Zoran; Török, Tibor +2 more
We simulate a coronal mass ejection using a three-dimensional magnetohydrodynamic code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R s is produced by a localized subsurface dipole superimposed on a global dipole field, mimicking the presence of an…
Observations of a Footpoint Drift of an Erupting Flux Rope
Aulanier, Guillaume; Dudík, Jaroslav; Gömöry, Peter +2 more
We analyze the imaging observations of an M-class eruptive flare of 2015 November 4. The pre-eruptive Hα filament was modeled by the nonlinear force-free field model, which showed that it consisted of two helical systems. Tether-cutting reconnection involving these two systems led to the formation of a hot sigmoidal loop structure rooted in a smal…
A Confined Partial Eruption of Double-decker Filaments
Yang, Shuhong; Chen, Yao; Zheng, Ruisheng +6 more
Filament eruptions, one of the most energetic explosions on the Sun, release large quantities of magnetized plasma into the interplanetary space. Hence, the understanding of the initiation and evolution of filament eruptions can provide broader implications for space weather and geospace climate. Here, we present a confined partial eruption of dou…
Manifestations of Three-dimensional Magnetic Reconnection in an Eruption of a Quiescent Filament: Filament Strands Turning to Flare Loops
Aulanier, Guillaume; Dudík, Jaroslav; Lörinčík, Juraj
We report on observations of the conversion of bright filament strands into flare loops during the 2012 August 31 filament eruption. Prior to the eruption, individual bright strands composing one of the legs of the filament were observed in the 171 Å filter channel data of the Atmospheric Imaging Assembly. After the onset of the eruption, one of t…