It is assumed that the age of the Sun is at least equal to the age of the Earth. The significantly larger source of solar radiation energy is nuclear rather than gravitational energy.
The geological age of the Earth is approaching five billion years; This is or is slightly greater than the age of the Sun, and the oldest stars in the Galaxy are more than 10 billion years old. The history of the Universe as a whole is 15 - 18 billion years old, and before the formation of modern planets, stars and galaxies, all its matter was apparently an almost homogeneous medium. The knowledge accumulated over many decades about the structure and evolution of celestial bodies, observational discoveries of the last half century and especially the discovery of the expansion of the Universe and the existence of isotropic cosmic microwave background radiation in it now make it possible to form a certain idea about the properties of the cosmic environment in the prestellar, pre-galactic era, about the physical processes that led to to the formation of the observable structures of the Universe from homogeneous matter. This is the content of modern cosmogony.
Thomson put forward a hypothesis according to which the radiation of the Sun is supported by gravitational energy released during its compression. Estimate the age of the Sun / using this hypothesis, assuming that in the initial state the matter of the Sun was evenly distributed throughout the entire infinite space, and in the final state the density of the solar matter is the same throughout the entire volume of the Sun.
We do not know the evolutionary age of the Sun with sufficient certainty, since we do not know the helium content in it. It is believed that the evolutionary age of the Sun lies somewhere in the region considered.
The value (1.2.33) agrees well with data on the ages of stars and galaxies (12 billion years), obtained on the basis of completely different considerations. It is also consistent with the geological age of the Earth (4 - 5 billion years), which serves as a lower limit for the age of the Sun.
The fuel that generates solar heat is thus hydrogen, and the product of its combustion is helium. It can be easily calculated that, with a constant release of energy, the hydrogen in the Sun will last for approximately 1011 years. The age of the Sun should be taken to be approximately 5 billion years. Consequently, only about one-twentieth of the original fuel supply has been consumed in it.
Solid lines show data for dust particles consisting of refractory substances, and dashed lines for dust particles consisting of volatile substances. For comparison, the arrows indicate the age of the Sun (right arrow) and the rotation period of the Galaxy at a distance corresponding to the distance of the Sun from the galactic center.
The energy released in this case turned out to be too great, and therefore after some time an explosion occurred in the form of a Supernova, during which the nuclei of the heaviest elements were formed; the mass of the star decreased due to the ejection of matter. This entire process could be repeated repeatedly until the mass of the central massive star fell below a critical limit. Such a system should have a lifetime of about 5 billion years, which corresponds to the age of the Sun and provides a time interval sufficient for chemical, geological and biological evolution to reach modern levels.
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How long does the Sun have left to live? Science answers this question this way: the age of our star is approximately 4.5 billion years. During this time, it managed to use up half of the hydrogen in its core. In other words, the Sun should have enough “fuel” for about another 4-5 billion years. This period is quite long, and humanity seems to have nothing to worry about. But recently, Dutch astrophysicist Piers van der Meer, an expert at the European Space Agency (ESA), compared data on the temperature of the solar core over the past 11 years and came to completely sensational conclusions. According to van der Meer, what is happening now on the Sun is very similar to the changes that precede a supernova explosion. According to a Dutch scientist, the temperature of the Sun's core, usually 27 million degrees Fahrenheit, rose to 49 million degrees in a few years. If the solar interior continues to heat up at the same rate, the process will become irreversible, and the Sun will inevitably explode in about six years!
Now imagine what an observer on a planet located in close proximity to an exploding supernova will see. At the request of Itogi, the apocalypse scenario was prepared by specialists from the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences. Approximately 8 minutes after the explosion, the entire sky will be filled with a monstrous flash, and this will be the last thing a person sees: along with the blinding light of the explosion, an invisible stream of X-ray, ultraviolet and gamma radiation will come with such power that it will overcome the protective layer of the atmosphere and kill in a matter of seconds everything is alive. The radiant energy of the explosion will heat the atmosphere and surface of the planet to temperatures of many thousands of degrees. Intense evaporation of the ocean will begin, the hot planet will be enveloped in hot steam. Through the dense scorching fog a monstrously bright ball will shine through, increasing in size. The night sky will become red-violet, with terrible stains: a luminous, expanding at a speed of several thousand kilometers per second, a hot cloud of ionized gas will gradually obscure the entire sky. Very quickly, streams of hot plasma from the exploding star will reach the planet. The atmosphere will be destroyed, and this will end the history of the Earth as a habitable planet. It will take a very long time before the melted radioactive “cinder” of a dead planet begins to slowly cool.
Impressive? Dr. van der Meer's calculations and conclusions are truly shocking. There is only one consolation: the Dutchman’s constructions are just a hypothesis, which many experts immediately questioned. For example, a senior researcher at the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences, Sergei Yazev, said in a conversation with an Itogi correspondent: “Dr. van der Meer’s conclusions regarding the increase in the temperature of the Sun’s core look very strange. Everything is just the opposite. Satellites, continuously recording the flow of solar radiation over the past decades, show that the rate of energy release of the main source of energy in our planetary system, as before, remains stable - every second the Sun emits energy equal to approximately 3.84 x 1026 joules. This value does not change at least. over the course of decades. Based on indirect evidence, we can conclude that the Sun has been shining in this mode for a very long time, that is, the same amount of solar energy falls on the Earth all the time.” Citing historical and geological data, scientists argue that the Sun has emitted and is emitting energy fairly consistently for at least several million years. If this were not so, they say, the Earth would bear traces of past ocean boilings or global glaciations. Fortunately, the “furnace” of the Sun worked and is working stably.
There are other arguments against van der Meer's hypothesis. In general terms, the mechanism of star death looks like this. As a result of thermonuclear reactions, the existing hydrogen “burns out”, and instead of it, nuclei of helium atoms and heavy elements - iron, cobalt and nickel - are formed. When the hydrogen fuel finally runs out, the outer shells of the star begin to rapidly “collapse” and fall inward, attracted by the massive iron core. As the density increases, electrons are captured by protons, resulting in the formation of neutrons and the release of a huge number of neutrinos. Neutrinos rush out. A powerful neutrino flow rising from the center of the star carries along the falling shell of the star, and it scatters in space with enormous speed - the star explodes. However, scientists claim that all this does not threaten small solar-class stars at all. For a star to explode and go supernova, it must be at least three times the mass of the Sun.
“In addition, astrophysicists are well aware of the signs of a so-called pre-supernova star,” says Sergei Yazev. “The fact is that the star’s spectrum can be used to determine its chemical composition. If there is little hydrogen there, but there are a lot of heavy elements, then the reserves of thermonuclear fuel have approached end, and soon - however, this "soon" may continue for many thousands of years - the phase of instability of the star should begin. But on the Sun, 90 percent of the atoms are hydrogen! And it will take a very, very long time for it to turn into heavier elements. that nothing dangerous in this sense is observed on the Sun."
Alternative doomsday scenarios, proposed, in particular, by American scientists, look much less dramatic. For example, Pennsylvania State University professor James Casting does not deny that the Sun, like any other star, is not eternal: “It inexorably becomes brighter and hotter. This leads to a gradual “dehydration” of the Earth. And this process will take on catastrophic proportions in no more than 5 years.” billions of years, as is commonly thought, but much earlier. Computer modeling shows that these processes could begin in about 500 million years." Fred Adams, a physicist at the University of Michigan, gives a more optimistic timeline: “There are about 3.5 billion years left before the cataclysm, and hardly anyone will observe the explosion of the Sun. It will destroy all life much earlier. And the already dead Earth will then be burned in as a result of an explosion that will consume, in addition to it, Mercury, Venus and Mars."
However, more exotic hypotheses have also been put forward. Thus, computer calculations carried out by American specialists show that there is a possibility that Jupiter, the largest planet in the solar system, will be torn from its orbit by a passing star. As a result of this cataclysm, the Earth will rush into the icy depths of the Universe, where it will freeze. However, this scenario is unlikely to be realized in the foreseeable future.
Nevertheless, in the coming years the Sun may present surprises to humanity. An authoritative specialist in the field of solar studies, head of the heliophysical laboratory of the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences, Vladimir Obridko, draws attention to the fact that at the beginning of the millennium there is a coincidence of several cycles of solar activity - 11-year, 22-year, 100-, 400- and 900 -summer. “Some kind of solar mess is coming, which cannot yet be predicted. We simply do not have sufficient knowledge of how a star behaves before an explosion,” says Vladimir Obridko. An accurate calculation of the behavior of the star is hampered by the lack of rigorous data, because according to all the rules, the Sun has been studied for just over a hundred years. Science still has very little information about both the structure and behavior of the Sun. Only now are heliophysicists around the world finally completing large-scale work to create a standard model of the internal structure of our star. Nevertheless, we are hardly talking about the imminent death of the solar system. Sergei Yazev, for example, is so sure of this that he is even ready to risk a large sum of money: “Taking this opportunity, I can offer Dr. van der Meer a bet of 10 thousand dollars. If after three years astrophysicists still discover clear signs that he is right , I give him the money. But if it turns out that the scientist’s assumption is not true, then I expect him to transfer it to my account.”
Humanity cannot imagine life without the brightest luminary visible to us. Why, “can’t imagine life”? Without sunlight, our planet would undoubtedly be simply uninhabited. Indeed, to this day our star is the main source of energy on Earth.
It was possible to more or less accurately determine how old the Sun is relatively recently, with the advent of super-powerful computers. No one can reliably indicate the age of the star, but based on computer modeling data, the star itself is approximately four and a half billion years old. Astrophysicists believe that this is not at all an advanced age for a cosmic body. It is believed that stars similar to our Sun in type and mass have a life cycle of ten billion years, and if so, then the center of our planetary system is at the peak of its development, almost exactly in the middle.
The further fate of the Sun
Of course, there is no point for us to look that far, but, nevertheless, it is interesting what will happen when the life cycle of the Sun comes to an end. Meticulous astronomers and astrophysicists have certain considerations in this regard.
In our time, the conversion of hydrogen into helium through thermonuclear reactions is actively taking place in the core of a star. Every second, approximately 4 million tons of different substances in the process of these physical and chemical cataclysms are converted into radiant energy, which, in fact, “feeds” all nearby planets, including our Earth.
The processes of thermonuclear reactions occur in such a way that as the amount of hydrogen decreases, the temperature of the Sun increases all the time and it shines brighter and brighter. This is, of course, invisible to us, but scientists say that in about a billion years, a star called the Sun will burn more than 10 times brighter. Accordingly, the temperature on Earth will also rise. Some scientists argue that within a billion years, life on earth will completely cease, with the exception perhaps in the ocean depths and under the polar ice caps. Finally, all forms of life on Earth will disappear in about 8 billion years - the Sun will become brighter at 40C on the surface of our planet, water will completely evaporate and the existence of living matter will become impossible. The Earth will turn into a semblance of the current Venus, and in another couple of billion years it will be completely absorbed by the Sun, which will “inflate” 256 times.
This is such sad news. We can only hope that in a billion years the level of our civilization will reach such heights that humanity will be able to cope with this scourge.
The closest star to us is, of course, the Sun. The distance from the Earth to it, according to cosmic parameters, is very small: sunlight travels from the Sun to the Earth in only 8 minutes.
The Sun is not an ordinary yellow dwarf, as previously thought. This is the central body of the solar system, around which the planets revolve, with a large number of heavy elements. This is a star formed after several supernova explosions, around which a planetary system was formed. Due to its location close to ideal conditions, life arose on the third planet Earth. The Sun is already five billion years old. But let's figure out why it shines? What is the structure of the Sun and what are its characteristics? What does the future hold for him? How significant an impact does it have on the Earth and its inhabitants? The Sun is a star around which all 9 planets of the solar system, including ours, revolve. 1 a.u. (astronomical unit) = 150 million km - the same is the average distance from the Earth to the Sun. The Solar System includes nine large planets, about a hundred satellites, many comets, tens of thousands of asteroids (minor planets), meteoroids, and interplanetary gas and dust. At the center of it all is our Sun.
The sun has been shining for millions of years, which is confirmed by modern biological research obtained from the remains of blue-green-blue algae. If the temperature of the surface of the Sun changed by even 10%, all life on Earth would die. Therefore, it is good that our star evenly radiates the energy necessary for the prosperity of humanity and other creatures on Earth. In the religions and myths of the peoples of the world, the Sun has always occupied the main place. For almost all peoples of antiquity, the Sun was the most important deity: Helios - among the ancient Greeks, Ra - the sun god of the ancient Egyptians and Yarilo among the Slavs. The sun brought warmth, harvest, everyone revered it, because without it there would be no life on Earth. The size of the Sun is impressive. For example, the mass of the Sun is 330,000 times the mass of the Earth, and its radius is 109 times greater. But the density of our star is small - 1.4 times greater than the density of water. The movement of spots on the surface was noticed by Galileo Galilei himself, thus proving that the Sun does not stand still, but rotates.
Convective zone of the Sun
The radioactive zone is about 2/3 of the internal diameter of the Sun, and the radius is about 140 thousand km. Moving away from the center, photons lose their energy under the influence of collision. This phenomenon is called the convection phenomenon. This is reminiscent of the process that occurs in a boiling kettle: the energy coming from the heating element is much greater than the amount that is removed by conduction. Hot water close to the fire rises, and colder water sinks. This process is called a convention. The meaning of convection is that denser gas is distributed over the surface, cools and again goes to the center. The mixing process in the convective zone of the Sun is carried out continuously. Looking through a telescope at the surface of the Sun, you can see its granular structure - granulations. It feels like it's made of granules! This is due to convection occurring beneath the photosphere.
Photosphere of the Sun
A thin layer (400 km) - the photosphere of the Sun, is located directly behind the convective zone and represents the “real solar surface” visible from Earth. Granules in the photosphere were first photographed by the Frenchman Janssen in 1885. The average granule has a size of 1000 km, moves at a speed of 1 km/sec and exists for approximately 15 minutes. Dark formations in the photosphere can be observed in the equatorial part, and then they shift. Strong magnetic fields are a distinctive feature of such spots. And the dark color is obtained due to the lower temperature relative to the surrounding photosphere.
Chromosphere of the Sun
The solar chromosphere (colored sphere) is a dense layer (10,000 km) of the solar atmosphere that lies directly behind the photosphere. The chromosphere is quite problematic to observe due to its close location to the photosphere. It is best seen when the Moon covers the photosphere, i.e. during solar eclipses.
Solar prominences are huge emissions of hydrogen, resembling long luminous filaments. The prominences rise to enormous distances, reaching the diameter of the Sun (1.4 mm km), move at a speed of about 300 km/sec, and the temperature reaches 10,000 degrees.
The solar corona is the outer and extended layers of the Sun's atmosphere, originating above the chromosphere. The length of the solar corona is very long and reaches values of several solar diameters. Scientists have not yet received a clear answer to the question of where exactly it ends.
The composition of the solar corona is a rarefied, highly ionized plasma. It contains heavy ions, electrons with a helium core and protons. The temperature of the corona reaches from 1 to 2 million degrees K, relative to the surface of the Sun.
The solar wind is a continuous outflow of matter (plasma) from the outer shell of the solar atmosphere. It consists of protons, atomic nuclei and electrons. The speed of the solar wind can vary from 300 km/sec to 1500 km/sec, in accordance with the processes occurring on the Sun. The solar wind spreads throughout the solar system and, interacting with the Earth's magnetic field, causes various phenomena, one of which is the northern lights.
Characteristics of the Sun
Mass of the Sun: 2∙1030 kg (332,946 Earth masses)
Diameter: 1,392,000 km
Radius: 696,000 km
Average density: 1,400 kg/m3
Axis tilt: 7.25° (relative to the ecliptic plane)
Surface temperature: 5,780 K
Temperature at the center of the Sun: 15 million degrees
Spectral class: G2 V
Average distance from Earth: 150 million km
Age: 5 billion years
Rotation period: 25.380 days
Luminosity: 3.86∙1026 W
Apparent magnitude: 26.75m
Everyone understands that without the sun life on Earth is impossible. Although it’s not only about him, but also about the optimal location of our planet from the Sun. And yet this does not downplay the importance of the celestial body, which provides us with vital warmth. What is the sun? Why is it “hot”?
What is the sun?
It is impossible to study the Sun directly. It is impossible to send a spacecraft to the Sun to study, to take samples and then study them. Therefore, our knowledge about the sun is based on theoretical calculations. Although it is said about the Sun that it “burns,” this is simply a transfer in simple language of the complex process that occurs in the Sun. Due to the vacuum in space, combustion in the usual sense of the word is impossible.
Observations helped to determine the mass, composition, radius and temperature of the Sun. Thanks to additional data, it became known that over billions of years the luminosity of the Sun has remained virtually unchanged. It was concluded that thermonuclear reactions take place in the sun. The temperature inside the sun reaches 20 million degrees. At this temperature, the hydrogen that makes up the Sun is converted into helium: four hydrogen atoms fuse into one helium atom. This process is the reason for the release of such a large amount of energy, a tiny fraction of which the planet Earth receives to support life on it. The photo below shows the thermonuclear process in the Sun.
Is our Sun a star or a planet?
In the ancient Russian chronicle, the Sun is a planet (due to objective reasons, it is clear why they thought so). Here are the signs of a planet as a celestial body:
- - the planet has a certain density;
- - the planet rotates both around its own axis and around the star;
- - the planet is massive enough to have a round shape due to its gravity, but not massive enough to trigger a thermonuclear reaction, like the Sun;
- - the chemical composition of planets like Earth contains iron, aluminum, silicon, titanium, magnesium and other similar compounds in large quantities. Gases are in the minority.
Although the Sun rotates around its axis, which is difficult to track, it
- - does not revolve around another star like a planet;
- - the composition of stars is dominated by hydrogen and helium gases. In the Sun, just over 73% is hydrogen, almost 25% is helium, the remaining 2% is other gases and some metals.
It is clear from everything that the Sun is a star.
How long will the Sun last?
Since everything in the Universe dies and is born again, the logical question is when will the Sun go out, if it goes out, of course? Or, conversely, can it explode?
At one time they said that the Sun's fuel reserves would last for another 5-6 billion years, and then it would begin to turn into a giant red star. Because of this, millions of hot gas will evaporate into the solar system and move the Earth away from the Sun. This, it seems, should not lead to disaster. But other calculations give only 1 billion years. Time will tell who is right and who is wrong, but humanity is unlikely to record the truth.
What happens if the Sun goes out? During the first week, temperatures will drop below 17 degrees Celsius. In a year, the temperature on earth will be minus 40. Photosynthesis will stop. There will be no basis for the survival of humanity. Within a million years, the temperature will stabilize at minus 160 degrees. Some microorganisms will be able to survive, but humans will not.
Regarding the explosion of the Sun, this can happen only after 6 thousand years. Over the past 11 years, the temperature of the solar core has doubled. If the trend continues, the Sun will explode before its possible extinction.
Should we worry that the Sun will one day go out or explode? Not worth it. Firstly, we will not live to see this, and, secondly, everything is born at some point, goes through its life path, and then passes away or dies.
Humans have a life cycle of one person within a hundred years, while stars have a cycle that takes billions of years.
What stage of its life cycle is the Sun in? The photo below shows what the life cycle of a star is like in general.
Since our Sun is a star, it must also go through this cycle. Our Sun is now in the yellow dwarf stage. The further stage is either a nebula or a red giant, and then a supernova and beyond. What exactly will be the scenario for our Sun, only time will tell. And that’s not for us...
At the moment, we can only study the Universe, admiring its greatness.