Did you know that the Sun that is seen every sunset is a star? Yes, although it seems huge compared to the stars we see at night, this is due to its proximity to Earth. Knowing the sun structure, you will know more about her.
The sun is the largest and closest star to the planet inhabited by human beings. It has the ability to generate energy and radiate it to the surrounding space, hence it is part of and is the center of the solar system, the planetary system in which it is located. The Sun is located in the center of the Solar System and is huge with a spheroidal shape. All the rest of the planets revolve around it. This star has been shining for 4.6 billion years.
How is the Sun studied?
Through different solar telescopes and satellites, the structure of the sun is known; one of them is SOHO, which is the Solar and Heliospheric Observatory. NASA, for its part, in 2018, launched the Parker probe to identify some features.
Scientists from disciplines such as astronomyFor centuries, scientists, including geology and others, have been looking to the sky and studying its phenomena to create theories about them. When the space age arrived, these studies saw the light of day, refining information with the support of nuclear physics.
The "nebular theory" states that a large molecular cloud had a gravitational collapse. This activity was the origin of the birth of many stars that were close to the encounter with other supernovae. This formed a shock wave that resulted in the formation of the Sun that shines today and that it is estimated will continue to do so for another 5 billion years.
Let's learn more about the Structure of the Sun
Here are some of the main features of the Sun that have been observed from Earth:
sun shape
Most of the bodies in space, which are observed from the ground through telescopes, are always seen in a spherical shape, this is due to the force of gravity that forms and contracts them on themselves. The sun is an imperfect sphere of gas, held together by gravitational pull and bulging slightly toward the equator.
Elements that make up the sun
Through a spectral analysis, it was possible to identify and separate the elements that make up this sphere of hot gas, which are going to be the same as the Earth and the other planets that make up the solar system. Because they were all created at the same time, only each one has different percentages of elements and the components of the sun are:
- 72% Hydrogen
- 26% Helium
- 2% other elements
Its glow occurs because hydrogen is being burned into helium, in that extremely hot center.
Size
Thanks to astronomy, the sizes of the celestial spheres can be known by establishing from Earth the «angular diameter» as ½ degree. The star king is enormous next to the planets; he has a radius 109 times greater than the terrestrial.
Distance in which it is
The studies about the distance between the Earth and the Sun were made through the "Astronomical Unit" and this showed that the distance is 150 million kilometers.
Movement
The solar surface has a period of rotation and through the Earth movements it is estimated that it takes 25 days at the equator, up to 36 days near the poles, and internally it rotates every 27 days.
Mass
Through a formula used in astronomy, where the weight between the planets and the galaxies is compared, it gives scientists the estimate that allows them to state that the sun has 332.946 times the mass of the Earth and constitutes 99.86% of the total mass Of the solar system.
Activity
The sun experiences periods of intense turbulence, which occurs cyclically. Sunspot flares appear through its magnetic fields, producing an entire electromagnetic spectrum. For more information on these, you can read about the sunspots.
sun density
Through the "Theory of Gravitation" it was possible to estimate the density. Although smaller than Earth because it is gaseous, its average density is around 1.4 g/cm3, higher than that of water.
Luminosity
This feature gives it its large size and solar radiation activity. In one hour it is capable of radiating on the planet what it needs for electricity in one year: that is 4 x 10 33 ergs/s or more than 10 23 kilowatts.
the temperature of the sun
It varies according to its layers and each one has a different temperature, although the surface is 10,000 degrees Fahrenheit, in its center it is 27,000,000 degrees Fahrenheit.
The constant activity of the sun makes hydrogen atoms very active through nuclear movement, transforming into helium and emitting a large amount of energy. All these physical characteristics make it possible for the energy emitted by the Sun to be used to generate heat and electricity.
When did the study of the Sun begin?
In 1869, the American scientist Jonathan Lane argued for the first time about the gaseous conformation of the Sun, about its gravitational force that keeps it in the sky and that it was made up of a central source of energy.
In 1874 J. Norman Lockyer published his research on the sun, in a large text, which was later called "Solar Physics" for his contributions in this area. At the beginning of the XNUMXth century, the Swiss-born astrophysicist Jacob Robert Emden wrote the first theoretical model about the Sun.
This scientist affirmed that the star king is a series formation of concentric gaseous layers, each layer has a pressure strong enough internally to withstand the weight of the gas, thus allowing gravitational attraction.
The studies that allowed "The theory of gravitation", admitted to make estimates of the density of the sun and recognized that it was higher than that of water. More than 100 years ago, with the development of spectroscopy, which studies physical bodies' relationship with electromagnetics, it was possible to deduce the temperature of the Sun from its brightness on the surface. This collaborated thus allowing estimates to be made about the chemical composition and its pressure.
In the 20th century, with more rigorous and precise instruments for observing the Sun, theories were reconsidered, and it was then possible to learn more and better about the Sun and its characteristics, and to generate more detailed and more satisfactory models, thanks to the development of atomic physics and electromagnetic theory, among others.
Composition of the Sun
According to the structure of the sun, which describes its size, mass, density and temperature, among others, it is also endowed with spectral characteristics.
At the beginning of the 1910th century, in XNUMX, Ejnar Hertzsprung and Henry Norris Russell designed the Hertzsprung-Russell diagram, known as the HR diagram, it is a stellar graph that shows the dispersion that exists between the stars according to:
- The relationship between the absolute magnitudes
- luminosities
- Spectral Classifications
- effective temperatures
- Measure its brightness compared to its temperature
At the same time, they wanted to know and disclose that:
"The way stars go through sequences of dynamic and radical changes through time".
The graph shows an area identified as main sequence. Where these stars are generally always and the researchers identified them by their spectral shape with a capital letter. G2 is the Sun's class of star.
Due to the composition of its elements, it is another of the classifications of the stars used in this graph, thus determining the stellar populations: I, II and III. At present, the Morgan-Keenan system is more widely used, for this coding of stars, letters and numbers were established to differentiate their temperature and size.
The biologist TH Huxley is reported to have said:
“The chessboard is the world; the pieces are the phenomena of the universe; the rules of the game are what we call laws of Nature. The player on the other side is hidden. We know that his game is always fair and patient. But we also know, to our cost, that he never overlooks an error, or makes the slightest concession for ignorance."
internal division of the sun
It is already known that the sun is the largest star in the Solar System and that its composition is not homogeneous. The structure is now described in order to know how many layers does the sun have internally. This sun structure it is impossible for it to be observed directly and hypotheses have only been made based on theories, based on its external characteristics. It is divided into 6 layers, distributed in well-differentiated regions, starting from the interior of the Sun.
Core
It is the center of the Sun, its temperature is approximately 15 million °C and its dimension is 1/5 of the solar radius. From there, the energy that the sun transmits is generated to fulfill its great nuclear function together with the prevailing pressures, which turn this center into a fusion reactor. The force of gravity acts as a stabilizer for this reactor, where reactions take place in which various chemical elements are produced.
At its most basic, hydrogen nuclei (protons) are converted into helium nuclei that are alpha particles, stable under the conditions that prevail inside the nucleus. Heavier elements such as carbon and oxygen are then produced. All these reactions release energy that travels through the interior of the Sun until it spreads throughout the Solar System, including the Earth. It is estimated that every second, the Sun transforms 5 million tons of mass into pure energy.
Radioactive zone
This area is where the energy concentrated in the nucleus will radiate. This large amount of extremely hot gas was formed in it and needs to be transferred, to release it and cool it. That accumulated energy is going to move through a radiation mechanism towards the outside. That material is a plasma, with a temperature lower than that of the nucleus, which contains an average of 5 million kelvins.
Through a slow process that takes about a month, this energy in the form of photons that come from the nucleus manages to approach the surface. Studies say that this delay in the journey to the outer areas, so that it becomes light, sometimes takes thousands and millions of years.
Convective zone
By delaying the arrival of photons from the radioactive zone, the gas reaches the extremely hot surface and there, with the temperature of this layer, drops rapidly to 2 million kelvins, reaches the surface, manages to cool down and returns to the center of the sun
In this part is where the energy is used to circulate the material and the gases that seek immediate release and possible cooling are found, to then start the process again, from the bottom of this area to the surface of the Sun.
When the energy arrives late, its transport is by convection, through the turbulence of gases at different temperatures. Using this energy, the heated atoms climb to the outermost layers of the Sun.
Photosphere
It is the layer that is perceived from Earth and is less thick than the sun, approximately 300 km thick and with a temperature that will exceed 5.000 °C. It is often referred to as the “sphere of light”, because it is from where most of the radiation that reaches us from the Sun is emitted.
These conditions of the Sun in a gaseous, hot and ionized state, makes its surface not be made of a tangible material.
It is made up of matter, which is mobilized full of shiny granules that last active between 5 to 15 minutes while they manage to radiate energy, cool down and return to the previous area.
The photosphere is observable from Earth Dimensions for humans, however, a specialized telescope with the relevant filters is required. There are devices for this, for beginners and for specialized scientists. When observed, the photosphere appears translucent at first, only to later appear as a dense material that does not allow it to be penetrated.
Chromosphere
This element is visualized as the outer part of the photosphere, full of red illumination and radiant emissions superimposed on it, it is a thin edge with respect to the other parts.
The composition of this layer is ionized gases that show strong magnetic fields and are more than 10.000 kilometers thick. The gases from the different layers will accumulate on this edge for their total release, reaching a temperature between 5.000 and 15.000 ºC.
When a solar eclipse occurs, it is feasible to see this part of the Sun's structure, the chromospheric gas is poorly absorbent and also poorly emitting, it is very transparent to most of the visible wavelengths.
Corona
This important layer of the sun is a magnetic field where high temperatures are produced and whose density is extremely low. This activity attracts bodies from the galaxy, such as asteroids, meteorites or others that circulate nearby.
The same are consumed and transported to take them to the center of the nucleus, thus being their food and subsistence to transform them into energy and finally turn them into ashes. By constantly feeding on the sun, it effectively releases heat that is required on Earth for survival.
It is estimated that the temperature of this layer is so high, due to the intense magnetic fields produced by the Sun. Every day at sunset, a band of faint light is observable around its ecliptic. This area groups a large amount of dust that manages to diffuse the light that is emitted from the photosphere and is called zodiacal light. 
In the corona they will also be in view, if an eclipse happens, the solar prominences, through loops that are made up of gas and much colder.
Heliosphere
It is a layer that blurs, composed of ions that come from the solar atmospheric layer together with its magnetic field. This zone of space is permeated by the solar wind and its magnetic field, reaching its irradiation passing through the orbit of Pluto. It has an outer edge called the heliopause.
Composition:
The elements that are traditionally known from the Periodic Table are in the different layers of the Sun. It is shown below what is the sun made of, distinguishing that hydrogen and helium are the most abundant elements.
|
Chemical components |
Symbol | % |
|
Hydrogen |
H |
92,1 |
| Helio |
He |
7,8 |
| Oxygen |
O |
0,061 |
| Carbon |
C |
0,03 |
| Nitrogen |
N |
0,0084 |
| Neon |
Ne |
0,0076 |
| Iron |
Fe |
0,0037 |
| Silicon |
Si |
0,0031 |
| Magnesium |
Mg |
0,0024 |
| Sulfur |
S |
0,0015 |
| Others | X |
0,0015 |
The investigations of the structure of the sun in the XNUMXth century, showed how each part is composed:
Crown: iron, nickel, calcium and argon were found in the form of ions. The Sun is no longer the same, through its millions of years of existence, it changes its percentages in terms of composition, this will continue to do so as it spends its supply of hydrogen and helium.
Discovering the Activity of the Sun
If a star is active, that is the sun. Externally as human beings, it can be observed daily, its rising and setting, but internally it is with a permanent turbulence of energy from its core to the rays that are perceived daily in solar activity. Magnetism plays a very important role in this activity. Among the main phenomena that happen on the Sun are:
the solar prominences
They are recognized by gaseous structures that remain at high temperatures and their size is imposing, they are formed in the crown and are named as prominences, bumps or filaments. They are distinguishable around the so-called solar ring, the Sun's magnetic field modifies them and presents them as elongated structures that intertwine.
coronal mass ejections
The great activity that happens internally in the layers of the sun, has a way of exiting matter at high speed that is ejected.
These ejections, which become coronal mass, last for long hours while the magnetic field lines remain. When these disappear, they dissolve and communicate with the earth's magnetic field and that is when human beings can visualize celestial spectacles such as the aurora borealis and aurora australis, which occur near the poles of the earth.
Sunspots
These spots are found in the photosphere. They are regions that appear above the solar disk as dark spots and have a lower temperature. They appear every 11 years. For more information, you can consult our .
With the help of space telescopes, scientists have been able to predict the number of partially successful spots in each cycle. These active spots are guided by the rotation of the Sun and are shown ahead with a larger spot that goes and another that closes the group.
Flames
The sun with the internal and external force it generates, one of its main activities is to expel material from the chromosphere and the corona. Through space telescopes and satellites, it has been possible to film these sudden and immense flashes, which sprout from the surface of the sun, which are known as flares.
Death
One of the characteristics of stars is that they die. The sun still has a long existence left. That nuclear fuel that its components have gives it many millions of years yet. Galactically, according to astronomers, the Sun will continue to give us its unstoppable energy.
When it dies and its elements are exhausted, life on Earth will also end. Suddenly it cannot happen, scientists assure that the way to die would be, that the Sun begins to enlarge and be a huge and reddish body, this action would generate the evaporation of the Seas and oceans from the earth.
The only way to see this death, which is estimated to happen in about 5 billion years, is that humans should already be settled on another planet.
La sun structure from its nucleus it would spread, in a destructive wave, ending the Earth and generating with that very bright gas, a great nebula. Inside it, the remains of the old sun would remain, becoming a very small "white dwarf", and the remnants of the old sun would remain inside, smaller in size than Earth, but much denser.
In about another 1000 billion years, it will cool very slowly, potentially taking several millennia to become a black dwarf. For now, it's worth continuing to study the Sun's structure and not worrying about its collapse, since by now the Sun has existed for more than half its life and awaits a long stay as Earth's star, for more than 7000 billion years, before its decline begins.
