Astronomy, Astrophysics and Space Science

Supernovae, Planetary Nebulae and Supernova Remnants

A supernova   is a powerful and luminous stellar explosion. A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. A planetary nebula, abbreviated as PN is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.