[question] why is there a halo around the eclipsed sun?

In this image of a solar eclipse taken from the Orion spacecraft (art002e009573 April 6, 2026) you can see a halo (probably not the right term) around the moon, supposedly from the hidden sun.

What is causing this? It cannot be an atmospheric effect, it does not look like the suns corona, and it obviously is not a camera effect since it is occluded by the moon.