"Once in a Lifetime" Earth's Sky to Host a Cosmic Event in a Few Days

The night sky is hosting the light of an exploding star after traveling 3,000 years across the galaxy, in what astronomers are calling a "once-in-a-lifetime" cosmic event.

Although it is difficult to accurately predict the exact date when T Coronae Borealis, also known as T CrB, will appear in the night sky, astronomers say it will appear as a very bright star that can be easily seen with the naked eye in the next few days or weeks.

In fact, the star T CrB was first observed more than 800 years ago, and has not been seen since 1946.

T CrB is a binary star system about 3,000 light-years away in our Milky Way galaxy, containing a small, Earth-sized white dwarf orbiting a red giant star, a star similar to the Sun in its early years, that is running out of nuclear fuel.

When the hydrogen in the heart of a red giant star runs out, it begins to collapse over billions of years and nuclear fusion stops, so it collapses in on itself and all its mass accumulates in its core, which becomes very dense but dimly luminous, and it turns into a white dwarf, that is, a dead star.

Astronomers explain that the star's bright light would be the result of a recurring thermonuclear explosion occurring within a binary star system. The white dwarf's gravity pulls hydrogen from the red giant, causing pressure and heat to build up until a massive explosion occurs every 80 years, powerful enough to travel 2,600 years to reach us and beyond.

This event, which most of Earth's current population will never happen again, is called a supernova, a sudden explosion in space that produces an intense burst of light and the formation of a new star.

“It’s a once-in-a-lifetime event that will create a lot of new astronomers, and give young people a cosmic event that they can observe for themselves, ask their own questions, and collect their own data,” said Dr. Rebecca Hounsell, an assistant research scientist specializing in supernova events at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The supernova event will be visible for about a week around the constellation Hercules (or Hercules), and can best be found using dedicated astronomy apps on a smartphone or tablet.

NASA scientists said the rare celestial sight could help inspire the next generation of astronomers. The supernova will also provide a unique opportunity to study the structure and dynamics of stellar explosions.

“Usually supernovae are so faint and distant that it is difficult to clearly pinpoint where the explosive energy is focused,” they added. “This will be really close, with lots of eyes on it, studying different wavelengths, and hopefully give us the data to start exploring the specific structure and processes involved.”