[이철환의 우주이야기] a heavenly star and an earthly star


[우리나라의 우주 개발이 속도를 내고 있습니다. 지난해 한국 최초의 우주발사체 ‘누리호’ 발사가 성공했고, 지난 8월 쏘아올린 달 궤도선 ‘다누리호’는 우주에서 영상과 사진, 문자를 보내오고 있습니다. 우주에 관한 높아진 관심과 호기심을 풀어주기 위해 경제관료 출신 이철환씨가 최근 출간한 <우주패권의 시대,4차원의 우주이야기>중 일부를 저자와 협의해 칼럼 형식으로 게재합니다]

A star is a celestial body that is fixed to the celestial sphere and barely moves relative to the constellation, and looks like a single point. However, real stars have very high temperatures and pressures in their cores, so nuclear fusion takes place. Stars emit light or heat with enormous energy created through so-called nuclear fusion reactions where hydrogen atoms combine with each other to become helium atoms.
The diameter of a star is usually about 100 times the diameter of the Earth, and the Sun, a stellar star, is the only star that emits light and heat of this size in the solar system that the Earth is belong to her. Therefore, planets, comets, meteors, etc. also have the letter ‘star’ attached to them, but they are not stars in the strict sense. The Sun, the representative star of the solar system, is an ordinary star, 109 times the diameter of the Earth and about 330,000 times the mass of the Earth.

When the star is expressed as a character or figure, it is sometimes used in a pointed shape such as ☆ or *, such as a pentagon or hexagon. This appears to be an abstraction of light rays sparkling and spreading from the bright stars in the night sky. In the case of a five-pointed star, it is called a pentagram, and the inverted form of the pentagram (pentagram) was adopted as a symbol of Satan, the devil. The six-pointed star is called Seren Dafydd and is currently used on the Israeli flag.

There are trillions of stars in the universe. Of these, only about 5 to 6 thousand stars can be seen in the night sky with the naked eye. This can only be seen in a very small part of the soot knight city. Furthermore, during the day the sunlight is too bright to see the stars. At night, when the sky gets dark, you can see the stars. The reason why stars do not shine as brightly as the sun is because they are so far out of the solar system. When viewed from Earth, it only appears as a tiny dot of light. The closest star to the Solar System is the star Proxima Centauri, about 4.3 light years from the Sun, and the farthest star exists in an outer galaxy tens of billions of light years away. 1 light year is about 9.5 trillion km.

Stars are often just like the sun, but like the relationship between the earth and the moon, there are many things where two stars are close and influence each other through gravity. These stars are called binary stars, and about half of all the stars in the sky are binary stars. Sometimes, in addition to two stars, it also exists in the form of multiple star systems containing three or more stars or clusters containing many stars.

Stars vary in brightness, colour, temperature, mass, size, chemical composition and age. First of all, stars are divided into apparent and absolute magnitudes according to their brightness. The apparent magnitude, or material magnitude, is a measure of a star’s brightness as seen from Earth. The brightness of a star is determined by the amount of radiation it emits. Accordingly, the closer the star is to the earth, the stronger the brightness, and the further away, on the contrary, the stronger the brightness, the weaker the light because the light is scattered when moving in distant space.

The brightness of a star is usually divided into 6 levels. The brightest star visible to the unaided eye is 1st magnitude, and the smallest star is 6th magnitude. However, if you use a telescope, you can see a fainter star. Stars fainter than 6th magnitude are referred to as 7th, 8th, etc. There are also many stars that are brighter than first magnitude stars.

A magnitude 0 star is brighter than a magnitude 1 star, and a magnitude -1 star is brighter than a magnitude 0 star. Stars with higher magnitudes are darker, and stars with lower magnitudes are brighter. The difference in brightness between 1st magnitude stars is about 2.5 times, with 1st magnitude stars 2.5 times brighter than 2nd magnitude stars and 2nd magnitude stars 2.5 times brighter than 3rd magnitude stars. Therefore, the brightness of a first magnitude star is about 100 times that of a sixth magnitude star. The sun is brighter than any other star. The magnitude of the sun is -26.7, and the magnitude of the moon at full moon is about -12.6.

Absolute magnitude is a magnitude of brightness assuming that each star is 32.6 light years or 10 parsecs apart. Since the absolute magnitude excludes the subjective factor when observing the brightness of a star, it can be seen to reflect the true brightness of a star better than the apparent magnitude. The Sun’s apparent magnitude is -26.7, but its absolute magnitude is only 4.8. However, the apparent magnitude of 4.8 belongs to a star so faint that it is difficult to see in a city with a lot of dust in the sky.

Each star has its own color ranging from blue to red. The color of a star indicates the surface temperature of that star, and in general, the ‘Colour Index’ becomes an important criterion for determining the temperature of a star. Referring to the color index, red and yellow stars that are thought to be warm colors are rather cool stars, and blue and purple stars that are considered cool colors are hot stars.

The hottest star is the purple star, which has a surface temperature of 42,000 K. This is more than seven times higher than the surface temperature of the Sun. It is followed by a blue star reaching 30,000 K. Yellow stars like the Sun are relatively cool, only 5,500 K, and red giants are even lower, only 3,800 K. K is named after the British physicist Kelvin, and is also known as absolute temperature as a unit of thermodynamic temperature. Looking at the relationship with Celsius temperature, which is widely used in everyday life, 0 (zero) K is -273.15 degrees Celsius.

The reason for this difference in general color sensation is that cool-colored stars are usually young stars, and warm-colored stars are slightly older. Young stars emit a large amount of radiant energy, so the color itself may look cold, but the temperature is very high, and old stars have a relatively low temperature because the amount of radiant energy is small.

The type of star is also determined by the size or degree of evolution of the star, including main sequence stars, giants, giants, white dwarfs, and neutron stars, black holes, etc. Among these various types of stars, the youngest are main sequence stars, while the oldest and most evolved stars are white dwarfs, neutron stars, and black holes. Neutron stars and black holes are not actually stars, but rather stellar debris or remnants.
And among the biggest stars, there are many supergiants with diameters hundreds of times larger than the Sun. The largest stars ever observed are Cygnus NML with 1,650 solar diameters, UY Scuti with 1,700 solar diameters, and Stephenson 2-18 with 2,150 solar diameters. The most massive star is R136a1 in Dorado, with a mass 265 times that of the Sun.

As such, a star, or star, originally referred to a visible celestial body. But stars aren’t just in the night sky. There are many stars on earth too. Singers, film stars, talents, comedians, athletes, etc., we call ‘stars’ those who are very famous and loved by the public in any field. Rather, it is more often used to refer to them in real life. Moreover, a popular person who is more famous than this star is called a superstar. A star is also called a celebrity, a celebrity, or a big trend.

Generally, stars are active in the fields of entertainment and sports, but social stars are also born as the frequency of use of social networking services (SNS) explodes. This refers to people who have a lot of followers on social media such as Instagram and Facebook. Usually, if you post your daily life on social media or upload information in a certain area, and your followers grow, there will even be an advertisement video attached. Although these social stars cost less to advertise compared to celebrities, they have a large following, and they are familiar and can give a sense of trust, so the advertising industry prefers them more and more .

Military generals and admirals are also commonly referred to as stars. They are also called ‘general’ because stars are included in their signification. When you become a general, you command and command thousands or tens of thousands of soldiers. Its influence on the country and society is also great. It is the highest rank in the army that defends the country, and it plays a vital role in determining the country’s destiny, especially during wartime.

These earthly stars have many opportunities to expose themselves to the public from the mass media. In addition, their words and actions and their properties become a hot topic in the market and sometimes influence the public by causing big and small trends. And with countless enthusiastic supporters, ordinary people live with wealth and honor that is hard to imagine. A lifetime star is a being who reflects the desires, dreams, fears, etc. of the public living at the time and is a target from which people derive vicarious satisfaction. Because of this, it is possible to look into the social aspects of the period through these stars.

Why do people like stars? A star is an object that brilliantly fulfills the part that people feel they don’t have. So people identify themselves subconsciously with their favorite stars. The moment people identify with a star, they feel vicarious satisfaction and enjoy the joy and happiness of escaping their harsh and shabby reality.
Furthermore, popular stars have become indispensable for the smooth running of the capitalist economy. This is particularly true in the area of ​​the cultural industry. This is because stars who act as models for advertisements are the most important link in driving consumer desire to buy. In addition, not only advertisements, but also everyday life such as living spaces, clothes, hobbies, and favorite foods of stars presented through the mass media become important factors that stimulate public consumption.

When there is a star, there are fans who follow and follow the star. Stars and fans need each other. And ‘fandom’ is a concept that comprehensively refers to the fan phenomenon and the consciousness as a fan. This is a common phenomenon in popular culture in industrialized societies. In general, fandom appears primarily in the field of popular culture rather than the field of classical art. In addition, fandom tends to appear more in women than men and in teenagers rather than adults.

Stars are beings that shine with their own power, whether on earth or in the sky. A star is a being that burns itself like the sun and gives light and heat to the surroundings. The same is true of the earth star. The stars in the night sky burn themselves to give light, and the stars on earth burn themselves to make their names known. The earth does not burn by itself. Therefore, the earth is not called a star or a star. The earth is just a planet. The moon doesn’t even ride It doesn’t get hot when the moon rises. The moon and planets emit light not because of their own power, but because they reflect the light of the sun.

To become a star like this, you have to work hard. And after becoming a star, comes a responsibility commensurate with the influence he wields. By fulfilling such efforts and responsibilities, a star is a being who burns himself and gives joy and happiness to those around him. If you appear on TV often but fail to bring joy and happiness to people, you are no longer a star.


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