Any Day Now, a Star will Explode in the Night Sky

Any day now, a white dwarf (or long-dead star) in the constellation Corona Borealis will explode in a brilliant nova.

Astronomers are urging Earthlings to keep their eyes peeled for a "once-in-a-lifetime" sight that hasn't been observed for 80 years.

Every 80 years or so, the stellar remnants accumulates enough material to trigger a thermonuclear explosion, known as a nova. The eruption will be as bright as Polaris, the North Star.

NASA and astronomers across the globe have been monitoring the system closely, with signs suggesting the eruption could occur any time between now and September 2025. The surprise factor makes it more interesting.

They don't know when it'll happen, and that's what makes it so special for spectators.

Novas are somewhat frequent galactic events, but many are not bright enough for the average viewer to observe.

Astronomers estimate between 20 and 75 occur each year, with only about 10 being spotted from Earth. Besides the Coronae Borealis nova, other recurring novae include Aquilae, Normae, Ophiuchi, Pyxidis, Sagittarii, and Scorpii.

A supernova is, likewise, the explosion of a star, but bigger. Supernovas are one of the most energetic events in the universe, capable of outshining an entire galaxy for a period of time.

These stars are about 8 times the mass of the sun when they exhuast their nuclear fuel and their cores collapse under gravity, triggering a massive explosion.

The last known supernova was observed on February 23, 1987. According to NASA, it blazed with the power of 100 million suns for several months.

Located in the nearby Large Magellanic Cloud, it is the nearest supernova explosion observed in hundreds of years and the best opportunity yet for astronomers to study the phases before, during, and after the death of a star.