When earth will die?
A team of international astronomers recently presented a scientific vision of the sun becoming a huge, bright ring of gas and interstellar dust, known as the planetary nebula, surrounding a small star representing the rest of its nucleus, according to the results of the research published in the journal “Nature Astronomy” several days ago.
When earth will die? The planetary nebula marks the end of 90% of active star life and tracks the star’s transition from being a red giant to a decaying white dwarf.
However, for years, scientists were not sure whether the sun in our galaxy would meet the same fate. Its mass was thought to be too low to create a visible planetary nebula. This question has been a mystery that occupies astronomers for 25 years about the secret of the brightness of planetary nebulae of low-mass stars such as the sun.
The origin of the paradox
This contradiction appeared 25 years ago, when astronomers observed bright planetary nebulae of supposedly small-mass stars, as the theory was saying — in the words of “Albert Zieglstra”, a professor at the School of Physics and Astronomy at the University of Manchester, and one of the authors of the study — that “you cannot get a bright planetary nebula from a star whose mass is less than twice the mass of the sun, so it is assumed that only large-mass stars give bright nebulae. ” Big stars of big mass.
When earth will die? Ashraf Ahmed Shaker, head of the galaxy and outer galaxies lab at the Egyptian National Institute for Astronomical and Geophysical Research, not participating in the study, said in a statement to Science: “What has baffled scientists throughout those years is the observation of many of these bright planetary nebulae inside elliptical galaxies. Galaxies) even though there are no stars with a large mass in that type of galaxy. “
Shaker explains: “Elliptical galaxies are also characterized by the lack of interstellar matter inside them, and the low rate of formation of new stars in them, which alerted scientists to the presence of something wrong in the theories that say that only large stars turn into bright planetary nebulae.”
Uncover the mystery of the mystery
“But our group showed, a few years ago, that there is a problem with those ancient models that explain the behavior of stars at the end of their lives,” adds Zieglstra to “science”: “We worked to compare how fast the nebula evolved with the speed that previous models said it should evolve.” “The two numbers were different by a factor of 3, and we published our claim that the previous models were wrong, as the stars evolve three times faster (at this stage of their evolution) than the aforementioned models.”
To reach these results, the scientific team used computer codes that specialize in studying a wide range of stars’ characteristics such as mass and luminosity, then comparing their evolution to confirm the new result, and it appeared that the data actually agree with the new model that suggests that “stars with mass less than 1.1 times the mass of the sun can produce A slightly faint nebula, and stars with masses equal to 3 times the mass of the sun will give a bright nebula and a very clear, and between them, the results agreed precisely with the model’s expectations, “according to Zieglstra’s statement to” Science “, who stresses that by saying:” We have solved the problem after 25 years old, and we can now expect that this method will work for most galaxies, but not for everyone. “
This means that in very old galaxies, in which star masses are lower than the permissible rate, this model shows that we will not find any bright nebulae that can be used to measure the distances between us and them, and in small galaxies, the stars will be so huge that they will not turn into a nebula. Planet, but it will explode in an image we call a “supernova.” This method will only work in galaxies whose stars range between 1 billion and 7 billion light-years old.
The end of the sun
To understand what the term “planetary nebula” means, we can start from the sun now, as it stands steady and stable between two forces. The first is the force of the massive pressure of the sun’s mass on its nucleus, but there is a second force that prevents the sun from collapsing due to the force of this pressure, it is nuclear fusion, so hydrogen It is the fuel of the stars, you incorporate it into the center to release the element helium, with a great deal of energy that keeps the star stable.
But when the sun’s fuel runs out of hydrogen, this fusion will stop, and then it happens that the inner envelopes of the sun collapse in on themselves, which drives the outer envelopes — as a reaction — to rapidly inflate and turn red due to the decrease in their surface temperature by almost half.
When earth will die? The star at that stage is called the “red giant”, in the case of the sun it will enlarge to reach its size almost to the Earth’s orbit, after which the sun will shake off its own outer shells — which represent about half of its mass — in the form of strong stellar winds that gather in cloud rings A colossal color to make what we call a planetary nebula, and it has nothing to do with planets, it is only a name given by ancient astronomers thinking they were planets.
Meanwhile, the nucleus of the star remains in the center of this nebular cloud and is called a “white dwarf”, Shaker says to “science,” adding that “planetary nebulae, then, are a transitional stage between red giant stars and white dwarf stars, as half of the giant star’s mass separates from it to form an envelope.” Gaseous around it, and that material is heated by the star’s core so that the brightness of that planet nebula reaches 10 thousand as bright as the sun, and this glow continues for about 10 thousand years. “ The material surrounding the star escapes into a raw material called (interstellar material) to form other stars when the appropriate conditions are available for that.
An unknown fate for human beings
When earth will die? As for ordinary stars, 90% of them turn into planetary clouds, whether bright or faint, ”Shaker says to“ science, ”continuing: As for the sun, it will turn into a faint planetary cloud surrounding a white dwarf. It will turn into a planetary nebula, but it will not have any degree of brightness that makes it visible, now we know that is not true, but what about Earth?
We do not, in fact, know the fate of the Earth by that period in the history of the sun, of course, it will not be suitable for life, but astronomers confirm that the moon is about four centimeters away from the Earth every year, which means that it will escape from its orbit within a billion and a half billion years, and the existence of the moon Necessary for life on Earth, which means that we will not be present until we witness the end of the sun. Perhaps humans will one day — after a tremendous technological development — have a technology that takes us from the solar system to a new one that can embrace life, but what we are sure of is that we At some point, we’ll need to run away from here!