For a star to explode as a supernova it problably starts out with a mass of at least 10 times of our sun.  It evolves into a red supergiant.  Unless it loses a large amount of its mass, the star becomes unable to resist the force of gravity, the core collapses, blowing the star apart.

To view the details on each supernova/remnant, including how I imaged it, just click on the name or the image.