Publications by authors named "Louise K Harra"
The High Resolution Imager (HRI) telescope of the Extreme Ultraviolet Imager (EUI) instrument onboard Solar Orbiter has observed EUV brightenings, so-called campfires, as fine-scale structures at coronal temperatures. The goal of this paper is to compare the basic geometrical (size, orientation) and physical (intensity, lifetime) properties of the EUV brightenings with regions of energy dissipation in a nonpotential coronal magnetic-field simulation. In the simulation, HMI line-of-sight magnetograms are used as input to drive the evolution of solar coronal magnetic fields and energy dissipation.
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- The Sun emits solar wind, a stream of ionized material, but its exact origin remains unclear.
- Researchers used Hinode X-ray Telescope to observe a solar active region near a coronal hole, discovering a continuous outflow of soft X-ray-emitting plasmas.
- These outflows are estimated to account for about 25% of the total mass loss rate of the solar wind, suggesting they could be a significant source of the solar wind itself.
I describe two of the most dynamic and highly energetic phenomena in the Solar System--the explosive flares that can occur when plasma is confined by magnetic fields and the large-scale ejections of material known as 'coronal mass ejections'. These explosive events are poorly understood and yet occur in a variety of contexts in the Universe, ranging from planetary magnetospheres to active galactic nuclei. Understanding why flares and coronal mass ejections occur is a major goal across a wide range of space physics and astrophysics.
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