Education, Secondary education and schools
The sun is ... The only star of the solar system
The sun is the center of our planetary system, its main element, without which there would be no Earth, no life on it. People have been watching the star since ancient times. Since then, our knowledge of the luminary has greatly expanded, enriched with numerous information about the movement, internal structure and nature of this cosmic object. Moreover, the study of the Sun makes a huge contribution to understanding the structure of the universe as a whole, especially those of its elements that are similar in nature and principles of "work."
Origin
The sun is an object that exists, by human standards, for a very long time. Its formation began about 5 billion years ago. Then in place of the solar system was a vast molecular cloud. Under the influence of gravitational forces, turbulence, like earthly tornadoes, began to appear in it. In the center of one of them, the substance (mainly hydrogen) began to thicken, and 4.5 billion years ago a young star appeared there, which after a long time was called the Sun. Around him gradually began to form the planet - our corner of the universe began to acquire the familiar form for modern man.
Yellow dwarf
The sun is not a unique object. He is classified as a class of yellow dwarfs, relatively small main sequence stars. The term "service", given to such bodies, is about 10 billion years. By the standards of space, this is quite a bit. Now our luminary, we can say, in the prime of life: not yet old, no longer young - half a lifetime still lies ahead.
The yellow dwarf is a giant ball of gas, the source of light in which are thermonuclear reactions occurring in the nucleus. In the glowing heart of the Sun, the process of converting hydrogen atoms into atoms of heavier chemical elements is continuously proceeding. While these reactions are being carried out, the yellow dwarf emits light and heat.
Death of the star
When all the hydrogen is burnt out, another substance, helium, will replace it. It will happen in about five billion years. Exhaustion of hydrogen marks the onset of a new stage in the life of the star. It will turn into a red giant. The sun will begin to expand and take up space all the way to the orbit of our planet. The temperature of its surface will decrease. In about a billion years, all the helium in the nucleus will turn into carbon, and the star will drop its shells. In place of the solar system will remain a white dwarf and the surrounding planetary nebula. This is the life path of all the stars like our luminary.
Internal structure
The mass of the Sun is huge. It accounts for approximately 99% of the mass of the entire planetary system.
The temperature in the solar core reaches 15 million Kelvin. Here, the highest density index, other inner regions of the Sun are much more sparse. Under such conditions, reactions of thermonuclear fusion take place, providing energy to the luminary itself and all its planets. The core is surrounded by a radiant transfer zone, then the convection zone is located. In these structures, energy is transferred by two different processes to the surface of the Sun.
From the nucleus to the photosphere
The nucleus borders on the radiant transmission zone. In it, energy is spread further through absorption and emission by the substance of light quanta. This is a rather slow process. From the nucleus to the photosphere, quanta of light fall for thousands of years. As they move forward, they move forward and backward, and reach the next zone transformed.
From the zone of radiative transfer, energy enters the region of convection. Here the movement takes place according to somewhat different principles. The solar matter in this zone is stirred like a boiling liquid: the hotter layers rise to the surface, the cooled ones descend in depth. Gamma quanta formed in the nucleus, as a result of a series of absorption and radiation, become quanta of visible and infrared light.
Behind the zone of convection is the photosphere, or the visible surface of the Sun. Here again, energy moves through radiant transfer. The hot streams from the underlying region that create the photosphere create a characteristic granular structure, which is clearly visible in almost all the images of the luminary.
Outer shells
Above the photosphere is the chromosphere and the corona. These layers are much less bright, therefore from the Earth they are accessible for observation only during a total eclipse. Magnetic flashes on the Sun arise precisely in these rarefied regions. They, like other manifestations of the activity of our luminary, are of great interest to scientists.
The cause of flares is the generation of magnetic fields. The mechanism of such processes requires careful study, including because solar activity leads to disturbance of the interplanetary medium, and this has a direct effect on the geomagnetic processes on Earth. The influence of the luminary is manifested in the change in the number of animals, almost all the systems of the human body react to it. The activity of the Sun affects the quality of radio communication, the level of ground and surface waters of the planet, and climatic changes. Therefore, the study of processes leading to its increase or decrease is one of the most important tasks of astrophysics. To date, not all issues related to solar activity have been answered.
Observation from the Earth
The sun has an impact on all living beings on the planet. The change in the duration of the daylight, the rise and fall of temperature directly depend on the position of the Earth relative to the luminary.
The movement of the Sun in the sky is subject to certain laws. The luminary moves along the ecliptic. This is the name of the annual way the sun passes. Ecliptic is the projection of the plane of the earth's orbit onto the celestial sphere.
The movement of the light is easy to see if you watch it for a while. The point at which the sun rises, moves. This is also characteristic of sunset. When winter comes, the Sun at noon is much lower than in the summer.
The ecliptic passes through the zodiacal constellations. Observation of their displacement shows that at night it is impossible to see those heavenly drawings in which the luminary is currently located. To admire is obtained only by those constellations, where the Sun stayed about six months ago. The eclipse is inclined to the plane of the celestial equator. The angle between them is 23.5 degrees.
Changing declination
On the celestial sphere is the so-called Aries point. In it, the Sun changes its declination from the south to the north. The light reaches this point every year on the day of the vernal equinox, on March 21. The sun rises much higher in summer than in winter. This is associated with a change in the temperature regime and the duration of daylight hours. When winter comes, the Sun in its movement deviates from the celestial equator to the North Pole, and in the summer - to the South Pole.
The calendar
The light is located exactly on the line of the celestial equator twice a year: in the days of the autumn and spring equinox. In astronomy, the time it takes the Sun to move from the Aries point and return to it is called a tropical year. It lasts about 365.24 days. It is the duration of the tropical year that underlies the Gregorian calendar. It is used today almost everywhere on Earth.
The sun is the source of life on Earth. The processes occurring in its depths and on the surface, has a tangible effect on our planet. The meaning of the luminary was already clear in the ancient world. Today we know quite a lot about the phenomena taking place on the Sun. The nature of individual processes has become understandable thanks to advances in technology.
The sun is the only star located close enough for immediate study. Data on the luminary help to understand the mechanisms of the "work" of other similar space objects. However, the Sun still keeps many secrets. They are only to be scouted. Such phenomena as the sunrise, its movement across the sky, the heat radiated by it, once also represented riddles. The history of studying the central object of our piece of the universe shows that over time, all the strangeness and features of the luminary find their explanation.
Similar articles
Trending Now