[Lady Jane]

"Look towards the Sun during a total solar eclipse (taking proper precautions of course) and you’ll see a beautiful, crown-shaped glow surrounding the Moon. It’s the solar corona – a hot plasma that extends millions of kilometres out into space. This region is a million times dimmer than the solar surface beneath, yet, strangely, it’s at least 1 million kelvin hotter. Seven decades after the unexpected observation was first made, it’s still one of the biggest mysteries in astronomy."

https://physicsworld.com/a/the-endur...-solar-corona/