Supernova Astronomy / by Julian, Mariella 650317, Beckett, Margurite, author 650316

“…The explosion expels much or all of a star's material at a velocity of up to 30,000 km/s (10% of the speed of light), driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. …”