Rare stellar explosion will ignite a "new star"

- [Dominic] Get ready to see a star explode.

Sometime between now and September, a bright light will appear in the sky and only be visible to the naked eye for a few days near the Hercules and Bootes constellations.

The light will actually be a massive explosion called a nova in a star system named T Coronae Borealis.

TCRB is made up of two dying stars, a red giant and white dwarf that orbit each other closely.

As the red giant expands and cools, gas from its outer layers is pulled onto the nearby white dwarf.

As this gas piles up on the small dense star, its interior gets hotter and hotter until it triggers a massive explosion, a nova, and that's what we'll see in the night sky.

A nova is different from a supernova, which is an explosion so enormous that the dying star expels its outer layers out into the universe, usually leaving behind a neutron star or a black hole.

TCRB explodes about every 80 years.

The last time it was visible was in 1946, but reports go as far back as 1217.

Now scientists are observing a similar pattern, a change in the star system's brightness, which is a harbinger for an upcoming explosion, and scientists expect it to explode again about 80 years from now.

(curious music)