An ECLIPSE is an astronomical event in which one celestial body, such as the moon or a planet, passes into the shadow of another. A NOVA is a star that suddenly increases in brightness due to a nuclear explosion on its surface. Novae are similar to novae, but they are caused by the accretion of hydrogen onto a white dwarf star. A solareclipse is an ECLIPSE in which the moon passes between the sun and Earth, blocking out the sun's light.