An artist's impression.
An artist's impression of an explosion in space. Scientists will today give the latest details on a phenomenon in the skies which has been delighting astronomers. They have been studying what is known as a recurrent nova - a star which explodes every few years. On February 12, amateur astronomers reported that a faint star in the constellation of Ophiuchus had suddenly become clearly visible in the night sky without the aid of a telescope. The recurrent nova RS Ophiuchi (RS Oph) has previously reached this level of brightness five times in the last 108 years, most recently in 1985. It consists of a white dwarf star in close orbit with a much larger red giant star. The two are so close together that hydrogen-rich gas from the outer layers of the red giant is pulled on to the dwarf by its high gravity.