Sounds like it is based on a misnomer, in that Nova is more seen by the common folk as something that's a bright burst or explosive force. Kinda like a Black Hole being a misnomer, in it not actually being a hole... but early astronomers named these things (Black Hole, Nova, Seas of the Moon) based on what was best known at the time. Technology will help science fix up the errors later, like proving earth isn't flat or that the sun revolves around it... and it will just take a while after that for the general public to know and accept it, if it's important enough.