The death of the Sun will wipe out life on Earth, but this is what could happen next

On our planet, the evolution of life has been characterized by a long path extending over several billion years. And when we thought about searching for life on other planets, young stars were the heroes of this search. However, recent research published in the journal Astrophysical Journal Letters It points to other unpredictable places where we might find life: If scientists are looking for new signs of life in the universe, maybe they should check something very old. Like an ancient star, astronomers say.

It appears that stars undergoing their own astronomical version of the midlife transition, and even those beyond their lifetime, may serve as promising locations in the search for extraterrestrial life.

Our star and many like it are destined to become red giants. It's the process that happens once a star runs out of hydrogen in its core. It goes through several stages. First, it is compressed, ignites the helium, and then inflates. When this happens, when the death of the sun comes, after several thousand years, It will completely wipe out any remaining life on Earth.

The red giants have shed their layers and what remains is a degenerate, compressed core. We call this dead star a white dwarf. the The death of the sun Therefore, it will be in the form of a white dwarf after passing through the red giant stage.

However, all is not lost. The researchers point out that without stellar winds and with great stability for billions of years, white dwarfs will represent an ideal place for life, as long as the planets survive the red giant stage and life develops after the appearance of the white dwarf.

The red giants have shed their layers and what remains is a degenerate, compressed core. We call this dead star a white dwarf. Hence the death of the sunIn the form of a white dwarf after passing the red giant stage.

but, All will not be lost. The researchers point out that without stellar winds and with great stability for billions of years, white dwarfs will represent an ideal place for life, as long as the planets survive the red giant stage and life develops after the appearance of the white dwarf.

New notes

In 1995, Swiss astronomers Didier Queloz and Michael Mayor announced the first discovery of an exoplanet orbiting a distant star called 51 Pegasi. since then, More than 5,500 planets have been found outside our solar system. When stars are born, they spin rapidly and create a powerful magnetic field that can explode violently, bombarding their planetary systems with harmful radiation and charged particles. Over billions of years, the rotation of aging stars gradually slows down; This is known as magnetic braking. Until now it was thought that this process would continue indefinitely.

“Weak magnetic braking stifles stellar winds and makes destructive volcanic events less likely,” explains Klaus Strassmeyer of the Leibniz Institute for Astrophysics.

But in the new study, scientists provide new data about how rotation and magnetism unfold in older stars They change after midlife. Metcalfe believes that his research has important implications for stars with planetary systems, as well as the prospects for their development for advanced civilizations.

The results of their observations revealed that magnetic braking changes suddenly in stars slightly younger than the Sun.. These stellar objects tend to become about 10 times fainter by that time, and appear to get dimmer as stars continue to age. Experts attributed these changes to an unexpected variation in the strength and complexity of the magnetic field, as well as the effect of this change on the stellar winds. This indicates that Older stars could represent a more stable environment for the evolution of complex life.

NASA estimates that 51 Pegasi is 23% more massive than our Sun. Their exoplanet is about half the size of Jupiter. It completes its cycle every four days, and astronomers believe that it is slowly moving towards its star.

References:

Weak magnetic braking in the exoplanet's host star 51 Peg

Travis S. Metcalfe 1, Klaus J. Strassmeyer 2, Ilya V. Ilyin 2, Derek Buzasi 3, Oleg Kochukhov 4, Thomas R. Ayres 5, Sarbani Basu 6, Ashley Chonto 7, Adam J Finlay 8, Victor C 9

View full list of authors Published 2024 January 5 • © 2024. The author(s). Published by the American Astronomical Society. The Astrophysical Journal Letters, Volume 960, Number 1, Citation Travis S. Metcalfe et al 2024 ApJL 960 L6 DOI 10.3847/2041-8213/ad0a95