This planet still lives, even without its Sun

Great first of astronomy: long theorized, the survival of an exoplanet after the death of its star has been proven.

When we dive into the bowels of the Milky Way, it’s hard to know what the Universe has in store for us. If our knowledge in astrophysics makes it possible to understand and explain a good number of phenomena, we must nevertheless distinguish two major types of knowledge.

Those that we have theorized, which are valid on paper, and to which scientists give some esteem. Then there are the “certain theories” those that physical observations have demonstrated. They can no longer be questioned, they have been proven.

Surviving planets

While humans have theorized on just about anything that is possible to imagine, researchers are now working to prove various theories, and thus make the link between what we “think true” and what is true. really is. In this mountain of work, astronomers who worked with the WM Keck Observatory in Hawaii were able to demonstrate that it was possible for an exoplanet to survive the death of its star.

This planet is located in a system 6,500 light years distant from ours. 1.4 times larger than Jupiter, it revolves around the remains of its star about 420 million kilometers away. Said like that, it may seem immense, but in reality it is less than the Sun-Jupiter distance in our planetary system (778 million kilometers).

How do the stars die?

Until now it was thought that when the stars died, the violence of the event reduced to nothing the planets that were around. But as this observation shows, it is not. When the star dies, it is actually because it lacks hydrogen.

So in the absence of fuel, gravity takes over, and the star’s core will begin to collapse on itself. At the same time, the outermost layers of the star will expand. It then takes the name of “red giant” and encompasses a large part of what surrounds it.

After about a billion years of expansion, the star will completely collapse, becoming a white dwarf. Then after billions of years of spinning like this, the star will eventually go out completely.

A duplicable model with us?

In view of this observation, the researchers hope that this model can be duplicated here in our solar system. Indeed, the Sun growing will absorb Mercury and Venus, the Earth, too hot, will be uninhabitable, if it is not also absorbed by the Sun.

Jupiter, and in particular the dwarf planet Ceres, could therefore become land of reception. Ceres is indeed an increasingly studied candidate. Located in the main belt (between Mars and Jupiter) it is likely to shelter life, it which has an ocean of liquid water as well as an atmosphere rich in water vapor because of its many geysers.

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