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A star in our sky could soon become thermonuclear, Earth prepares for action

Posted on by angelo
A star in our sky could soon become thermonuclear, Earth prepares for action

The sky from our planet is a fascinating place if you don’t think about it a lot, but if you really think about it, there’s not much going on up there. The multitude of stars visible from Earth have been in the same place for ages, the planets are generally not visible from here, and no alien spacecraft have arrived so far. So when a nova is about to occur and it will be visible from Earth, human hearts are about to start beating a little harder.

Nova is the term we use to describe sudden bursts of light in the sky, caused by the eruption of accumulated stellar matter following a sudden thermonuclear explosion. In turn, the explosion is caused by the accumulation of hydrogen on the surface of the star.

Unlike supernovae, which are the final manifestations of dying stars and catastrophic events, novae occur regularly over periods of thousands of years because the star itself is not destroyed in the process. . And if the conditions are right, we humans have the chance to experience such events for ourselves.

I don’t know how many of you have heard of a place called T Coronae Borealis (T CrB). Also known as the Blaze Star, it is a binary system located in the North Crown region, 3,000 light years from our world. It is home to a white dwarf and a red giant.

The red giant, an ancient star, is stripped of its hydrogen by the gravitational pull of the white dwarf, and the substance builds up on the surface of the smaller star until it can no longer withstand the pressure and the heat. Every 80 years or so, the white dwarf erupts in a glorious thermonuclear explosion visible from Earth.

T Coronae Borealis System

Photo: NASA

The first time humanity learned about this nova was in 1217, and we know this from the account of a German abbot named Burchard. The last time the place exploded was in 1946, which means there’s a very good chance, according to astronomers, that it could do so again by September of this year.

This prediction is supported by the fact that the white dwarf behaves the same way it did before it exploded after the end of World War II. The most telling sign: a dark spot in the region of the sky where the star is located.

If it explodes, the nova will become a “a once in a lifetime event” because, despite its regularity, the explosion does not happen often enough for human beings to experience it twice in their lifetime.

The fact that the nova is located relatively close to our planet makes it a prime study target. Astronomers will have to be quick, however, as the event won’t be visible for more than a week.

Knowing the event was going to happen, NASA gave us some directions on where to look in the sky – a fair warning, though, because following these instructions isn’t possible without a basic knowledge of the night sky.

First, we should locate the North Crown, a horseshoe-shaped collection of stars to the west of the constellation Hercules. To do this, you must first observe the two brightest stars in the Northern Hemisphere, Arcturus and Vega. You have to follow an imaginary straight line from one to the other, and this exercise will reveal the location of the Corona Borealis.

T Coronae Borealis System

Photo: NASA

A number of telescopes, both on the ground and in space, will be pointed at the distant white dwarf in the coming months, including the Fermi Gamma-ray Space Telescope, the James Webb Space Telescope, and the Neil Gehrels Swift Observatory, among others. others. .

They will be used to capture data on the visible and non-visible light spectrum, but, for the first time, they will also observe the event using gamma ray imagers, a technology that has not previously been available in 1946.

NASA and the astronomer community at large also rely on the general public to gather information about the nova, especially in its early stages.

Once the event is over and all the data is available, people will start looking through it in hopes of learning more about “the structure and dynamics of recurring stellar explosions like this.” Then, a better understanding of the life cycles of binary systems and their internal processes could also be obtained.

While all of the above sounds exciting, there is a small chance that September will pass without the T CrB exploding.

“Recurring novae are unpredictable and counter-current,” said Dr. Koji Mukai, an astrophysics researcher at NASA Goddard. “When you think there can’t be any reason why they follow a certain established pattern, they do – and as soon as you start relying on them to repeat the same pattern, they deviate from it completely. We will see how T CrB behaves. »