Nova-Like Star

a star that resembles a nova in the nature of the brightness variation or spectrum. The term is very indefinite since it includes objects of different luminosities, spectra, and physical natures, both binary and single. Stars that are not variables or that vary weakly are sometimes included in the class of nova-like stars because their emission spectra resemble the spectrum of a nova near maximum brightness. Variable stars are termed nova-like stars if they experience abrupt changes in brightness in which the increase proceeds many times faster than the decrease, and if they have an emission spectrum. The brightness of nova-like stars varies substantially less than that of novae.