Starwatch: Exploding nova promises rare sight in coming months

Records show T Coronae Borealis outburst occurs every 80 years or so and is expected between now and September

Get ready for a new" star to appear in the night sky. Not really new of course, but a star that is now below the naked-eye visibility limit is gearing up for an outburst that will bring it within sight of the unaided eye for the first time since the 1940s.

Such a star is called a nova, Latin for new". The star, T Coronae Borealis, is actually composed of two stars: a red giant and a white dwarf. The white dwarf is a dense stellar core about the size of the Earth and its gravity is pulling gas off the red giant. This gas accumulates on the white dwarf's surface before detonating in a thermonuclear explosion, causing the star to temporarily brighten. Eventually, it returns to normal and the cycle repeats.