What is a Supernova Remnant?
A supernova remnant is simply what is left over (i.e. the remnant) of a supernova. That probably isn’t a very helpful definition, so I’ll try to explain what I mean. First, I should probably define what is meant by the term “supernova.” A supernova is simply the explosion of a star. Keep in mind, the average star is a million times more massive than the entire Earth, so we’re talking about an incredible explosion here. The energy released in a typical supernova is on the order of 1044 joules. (A joule is simply a unit of energy that physicists use). 1044 is a 1 followed by 44 zeroes! There is no comparison for this amount of energy that is even meaningful. Supernovae are so powerful that they can be seen from halfway across the universe (billions of light years!). Here we can draw a comparison. The farthest star you can see with your eye on a dark night is only a few thousand light-years away. I’ll need to talk about what causes a supernova, because it is somewhat relevant here. Stars
