The names of the main characters are explained in the novel. Mal’s complete name is Malvolio, who is a character in Shakespeare’s Twelfth Night. Malvolio is the steward of Olivia’s household in William Shakespeare’s comedy Twelfth Night, or What You Will. He is often portrayed as the main antagonist.
Nova is named after a star. A nova is an astronomical event that causes the sudden appearance of a bright “new” star, that slowly fades from view over several weeks or many months. Novae should not be confused with other more energetic astronomical phenomena known as supernovae (SNe), which catastrophically destroys massive stars or white dwarfs.