The Cygnus Loop is a large spheroidal supernova remnant. What we are really looking at is material either blown out from the supernova star or gathered up by the shock fronts moving out from the explosion. If large enough, a star will undergo a supernova explosion when it is running out of fusing fuel and can no longer sustain its volume against gravity. While the core of a dying star implodes, the sudden release of energy causes a lot of the star to explode violently with both material and light. This supernova was astronomically fairly close to us at just 1500 light years away, and occurred between 5000 to 8000 years ago. At the time, the starry explosion would
Its Supersonic! – But it’s complicated
