Cosmology Views

Comparing Stellar Corona to Galactic Corona

These two terms share their second word but are described very differently. Perhaps they are a similar plasma phenomenon.

From Wikipedia:

A corona (Latin for 'crown'') is an aura of plasma that surrounds the Sun and other stars. The Sun's corona extends millions of kilometres into outer space and is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. Spectroscopy measurements indicate strong ionization in the corona and a plasma temperature in excess of 1000000 kelvin, much hotter than the surface of the Sun.

From Wikipedia:

The terms galactic corona and gaseous corona have been used in the first decade of the 21st century to describe a hot, ionised, gaseous component in the galactic halo of the Milky Way. A similar body of very hot and tenuous gas in the halo of any spiral galaxy may also be described by these terms.

This coronal gas may be sustained by the galactic fountain, in which superbubbles of ionised gas from supernova remnants expand vertically through galactic chimneys into the halo. As the gas cools, it is pulled back into the galactic disc of the galaxy by gravitational forces.

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A spiral galaxy has a galactic halo around the galactic corona. The descriptions  of the galactic halo imply its only purpose is to hold dark matter.

The 'superbubbles' and 'chimneys' sound like the 'Fermi bubbles' and the birkelund current pair at the galactic core. I do not recall their association with the galactic corona. The 'fountain of hot gas' is a bad joke.

The Sun's diameter is about 1.4 million km so the solar corona is described as extremely hot plasma extending a multiple of solar diameters. In some solar eclipse images the corona appears as almost a continuum of plasma filaments, from the solar surface, with all perpendicular creating this crown.

In the electric Sun, this corona is the electric discharge on the anode in the solar circuit extending to the heliopause..

I could not find a Thunderbolts EU guide having a reference to a galactic corona.

Chandra has imaged distant galaxy clusters where much of the plasma in the intracluster medium is active in X-ray; this  is the medium, not just a filament.

This comparison between two uses of the word corona suggests interesting questions which might be impossible to answer without an in situ measurement.

Is a galaxy an anode in the local galaxy cluster where its cathode is a sphere around the intracluster medium, behaving like the heliopause on this scale of a galaxy cluster?

Is a galactic halo actually the galactic corona electric discharge diminishing over distance?

There is more happening around the Milky Way bulge than I knew.

My memory is failing. On September 29, I posted :
Analyzing a Galaxy Halo

A fast radio burst observed passing through a galactic halo revealed a weak magnetic field.

A magnetic field requires an electric current.