The largest star in the solar system would be approximately 4.6 billion years old and have about 10 billion more to exist, according to a recent article in the American scientific journal Science Alert based on research published in Nature Astronomy. What will happen on that journey?
According to the publication, the Sun increases its brightness at great speed: 10% every billion years or so. That incessant increase would end “life on Earth” as we know it as it would lead to our oceans evaporating and “the surface getting too hot to form water.”
In about 5.5 billion years, the closest star to Earth would become a “giant red rock”, its core would shrink but its outer layers would expand to Mars and envelop our planet in the process. And in 10 billion, it would end its existence, it would go out. “One thing is for sure: by then, we will no longer be there. In fact, humanity only has about a billion years left unless we find a way out of this rock, ”the article says.
What does it mean that the Sun will turn into a red giant star? “The stars are a bunch of dust gases that over time are compacted by gravitational attraction, until a moment comes when the pressure inside this object is such that hydrogen begins to have a nuclear reaction,” the doctor introduced to Infobae. in Mechanical Engineering Alejandro Farah, academic at the Institute of Astronomy and head of dissemination of the University Space Program of the National Autonomous University of Mexico.
“When the hydrogen is fusing and the object becomes very hot, there comes a time when the gravitational attraction has to be balanced towards the center of that sphere and it becomes so hot that the hydrogen begins to have other types of more energetic nuclear reactions. Then quickly, at stellar scales, it expands into a red giant, ”explained Farah, a specialist in mechanical design of astronomical instruments. This means that, somehow, “it overcame that gravitational pull and can expand up to 100 times its size quickly.”
Although it is complex to detail what will happen next, the study published in Science Alert used computer models and found that it is likely that this giant red rock, as well as 90% of the stars, will become a “white dwarf”.
“One thing is for sure: by then, we will no longer be there. In fact, humanity only has a billion years left unless we find a way out of this rock, ”the article warns.
In this sense, Farah explained to Infobae that on Earth we have “an electromagnetic field” that protects us from strong solar radiation. “The temperature of the red giant will be a few thousand degrees Celsius and it is impossible for there to be life at those temperatures. Before it reaches Earth, he assured, the radiation will sweep the atmosphere and dry up all the seas. “
—After becoming a giant red star, how will it envelop the Earth and what does it mean that it will become a “white dwarf”?
—A red giant, after a while, somehow sheds the outer layers, explodes, and a planetary nebula is generated. A white dwarf is a remnant left over from the star’s evolution, because it has used up so much of its nuclear fuel. In that nucleus there is oxygen and carbon, but mainly there is still hydrogen, and it arrives at that moment with a kind of energetic balance, with a temperature and gravity that lasts a very long time. Most stars are going to have this process and be in this state for a very long time. This white dwarf becomes an object less and less bright, it is cooling and, in the end, it enters a kind of death. This is under investigation, and what is said is that it will be a kind of black object that will reach the temperature of its environment.
“Why is the Sun increasing in brightness by about 10 percent every billion years?”
“It is a natural process in the evolution of stars.” As it is compressed by gravitational attraction, there are more nuclear reactions and that causes more energy to emanate. There comes a time when it becomes unbalanced because being hotter and more compacted, it tends to expand. It is like a heart beating for millions of years: it compacts, heats up and expands, over and over again until the process of becoming a red giant begins. In fact, it is believed that this will happen to most stars, but there is still a long way to go and there are still no certainties.
“Is there anything we can do to prevent it?”
—It is a very important question and difficult to answer. The imagination of the human being has no limits but today we do not have the technology to avoid it. However, we must continue to move forward and try to migrate to places where that does not affect us. You have to understand well how the stars evolve, what is happening, to be able to migrate to Mars for example, which at some point will be habitable. It is believed that a base could be put there in about 15 years, for research on the planet and to go planning the possibility of establishing a population in the future. The base is important to establish the infrastructure to take advantage of the planet’s natural resources. It is important to explore and leave our beautiful planet in order to survive and achieve the super-existence of the human race in other places.
“When the Sun dies, will there be no more light in the universe?”
—The universe is much more than our Sun. It is estimated that there are more than 1 million times as many stars in the visible compared to all the grains of sand on beaches, deserts and oceans in the world. When the Sun passes its final stage, there will continue to be light in the universe. There is another theory that a long time later the universe will freeze, but that is not intrinsically linked to our Sun, and we are literally beginning to imagine all this, there are still no accurate theories. This is going to happen in billions of years and there is no need to worry, but we must keep it in mind and prepare because it is something very important.