Comparison of an LBV and the Sun. Credit: University of Florida/Meghan Kennedy.
P Cygni is a good example of an LBV, it has many interesting characteristics in its own right. It was discovered on August 8th, 1600, when it suddenly appeared, flaring up to 3rd magnitude. Over the next hundred years it continued to fade and brighten up what allowed it to be considered as variable. Flares have also been associated to the variability of the star when it brightens.
It now seems possible that the flares may be due to the presence of a second star in orbit around P Cygni. (read more)