CfA: A Look Inside the Central Engine of a Solar Flare

[bystander]

A Look Inside the Central Engine of a Solar Flare for the First Time
Harvard Smithsonian Center for Astrophysics | 2020 Jul 27

Observation of a large solar flare on Sept. 10, 2017 in extreme ultraviolet (grayscale background, by NASA's Solar Dynamics Observatory) and microwaves (red to blue indicate increasing frequencies, observed by the Expanded Owens Valley Solar Array). Light orange curves are selected magnetic field lines from the matching theoretical solar eruptive flare model. The flare is driven by the eruption of a twisted magnetic flux rope (illustrated by a bundle of color curves threading the dark cavity). Microwave sources are observed throughout the region below the cavity where a large-scale reconnection current sheet — the flare's 'central engine' — is located, providing crucial measurements for its physical properties. Credit: NJIT-CSTR, Chen, Yu; NASA SDO

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Scientists from the Center for Astrophysics | Harvard & Smithsonian and the New Jersey Institute of Technology today announced the first successful measurement and characterization of the "central engine" of large solar flare. The findings, published today in Nature Astronomy, reveal the source of the intense energy powering solar flares.

According to the study—which closely examined a large solar flare accompanied by a powerful eruption captured on September 10, 2017, by the NJI's Owens Valley Solar Array (EOVSA), at microwaves—the intense energy powering the flare is the result of an enormous electric current "sheet" stretching more than 40,000 kilometers—greater than the length of three Earths placed side-by-side—through the core flaring region, where opposing magnetic field lines approach, break, and reconnect. ...

Measurements taken during the study also indicate a magnetic, bottle-like structure located at the top of the flare's loop-shaped base, or flare arcade, at a height of nearly 20,000 kilometers above the surface of the Sun. The study suggests that this is the primary site where a solar flare’s highly energetic electrons are trapped and accelerated to nearly the speed of light. ...

Measurement of Magnetic Field and Relativistic Electrons Along a Solar Flare Current Sheet ~ Bin Chen et al

• Nature Astronomy (online 27 Jul 2020) DOI: 10.1038/s41550-020-1147-7
• arXiv.org > astro-ph > arXiv:2005.12757 > 26 May 2020

[neufer]

A Look Inside the Central Engine of a Solar Flare for the First Time
Harvard Smithsonian Center for Astrophysics | 2020 Jul 27

Scientists from the Center for Astrophysics | Harvard & Smithsonian and the New Jersey Institute of Technology today announced the first successful measurement and characterization of the "central engine" of large solar flare. The findings, published today in Nature Astronomy, reveal the source of the intense energy powering solar flares.

Measurements taken during the study indicate a magnetic, bottle-like structure located at the top of the flare's loop-shaped base, or flare arcade, at a height of nearly 20,000 kilometers above the surface of the Sun. The study suggests that this is the primary site where a solar flare’s highly energetic electrons are trapped and accelerated to nearly the speed of light. ...

Measurements indicate a bottle-like structure located at the top of the bystander's loopy-shaped base at a height of nearly 20,000 posts. This is the primary site where highly energetic plectrons are trapped and accelerated to nearly the speed of Dwight.