A nova remnant is made up of the material either left behind by the gigantic explosion of a star in a nova

Nova

A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...

, or from the bubbles of gas blasted away in a recurrent nova. It has an expansion velocity of around 1000 km/s, and has a lifetime of a few centuries. Considering their short lifetimes, nova remnants usually do not exist anymore by the time their light reaches us. Nova remnants are much less massive than supernova

Supernova

A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

 remnants or planetary nebulae.

External links

• T Pyxidis Nova Remnant (HubbleSite)
• Double-star systems cycle between big and small blasts (The Carnegie Observatories)
• Nova Remnant comparison table (UOttawa)
• Nova Remnant (UOttawa)