What is Astronomy

What is Astronomy?

Astronomy The study of the light, origin, structure and behavior of celestial bodies located in the universe is the subject of astronomy. The part of the universe that has been detected so far is estimated to contain about 19 billion galaxies and each galaxie contains about 10 billion stars. The diameter of the Milky Way is about one lakh light years. Primitive life on our earth was born 2 billion years ago and man's descent on earth took place 10-20 million years ago. According to scientists, this universe originated from the explosion of a giant body.

The Sun is an average star with eight main planets, Earth being one of them. Every star in this universe is like the Sun. There are many stars in front of which their sun does not stand even equal to the atom (particle). Just as there are planets of the Sun and by combining them all we call the name of the solar family, in the same way each star has its own family. Many people think that the Sun is stationary, but the entire Solar System is also moving at a speed of 13 miles per second within the local constellation system. The local constellation system is moving under the galaxies at a speed of 200 miles per second and the entire galaxy is moving in different directions under the distant outer galaxies at a speed of 100 miles per second.

What is space?

Simply put, space is a vast, empty space without air, whose boundaries extend to infinity in all directions. The solar system, numerous stars, stellar dust and galaxies are all components of space. There is no wind in it, and there is no cloud. Day or night, space always remains black. No animal lives in space. Because of the vacuum, no living being can survive there. There is no information about the fact where space begins. Space surrounds us. To explain, all we can say is that space begins where Earth's atmosphere ends.

What is universe ?

The universe is the whole of time and space and its contents. The universe includes all the planets, stars, galaxies, celestial bodies, the contents of the space between galaxies, nonatomic particles, and all matter and all energy. The diameter of the observable universe is currently about 28 billion parsecs (91.1 billion light-years). The diameter of the entire universe is unknown, and may be infinite.

  • Under the universe, all those celestial bodies and meteors and the whole family, which includes the sun, moon, earth etc., are studied.
  • The regular study of the universe was started by Claudius Ptolemy (in 140 AD).
  • According to Ptolemy, the Earth is at the center of the universe and the Sun and other planets revolve around it.
  • In 1573 AD, Copernicus accepted the Sun as the center instead of the Earth.
  • The space between the earth and the moon is called cislunar.

Scientific hypothesis of the origin of the universe:

  • Big Bang Theory – George Lamentor
  • Theory of Perpetual Origin – Thomas Gould and Human Bondi
  • Theory of Contraction Release – Dr. Ellen Sandies
  • The most modern source of information about the universe, Prof. By Jyokarai Burbidge, who propounded that each galaxy emits a significant amount of helium as a result of thermal nuclear reactions.
  • Light year is the distance which is 29,7925 km in light void. per se. Or about 186282 mph. determines the speed.
  • The cosmological unit refers to the average distance between the Sun and the Earth which is 149597870 km. (about 149600,000 km.) or 15 km. Is.
  • The Sun and its neighboring stars normally orbit 150 km in a circular orbit. per cent. revolves around the center of the galaxy at an average speed of . At this speed the Sun takes 25 crores to complete one revolution around the center; It takes years. This period is called the cosmic year.

What is galaxy?

Akash Ganga or Kshirmarga is the name of the galaxy in which our solar system is located. The galaxy is a spiral galaxy in shape, with a large center and several curved arms extending from it. Our solar system is located on its hunter-swan arm (Orion-Cygnus arm). There are between 100 billion and 400 billion stars in the Milky Way and it is estimated that there are likely to be about 50 billion planets, of which 500 million are at a distance of 'life-friendly temperature' from their stars. A survey conducted in 2011 found the possibility that there may be more planets than this estimate - according to this study, there may be twice the number of stars in Kshirmarga. Our solar system is located at the outer edge of the Milky Way and revolves around its center. It takes about 225 to 250 million years to complete one complete orbit.

What are stars?

Stars are massive, celestial bodies rich in self-luminous mass of warm air. Their personal gravity keeps their matter organized. Many stars with twinkling light, scattered like dots of light, are visible in the cloudless sky at night. Sun is a big star.

Important facts about wiring:

  • Stars are formed from clouds of gas in the galaxy. Energy is emitted continuously from stars.
  • 98 percent of the Galaxy is made up of stars. These are spherical bodies located in the hot and radiant universe of gaseous matter.
  • The Sun is also the star that is closest to the Earth.
  • Cyrus is the brightest star seen from Earth.
  • Vamana Tara is the star whose Jyotsna is less than that of the Sun.
  • The ecstasy of huge stars is more than the Sun like Betelgeuse, Sirius, Antaris.
  • Nova A star whose brightness increases from 10 to 20 due to the ejection of gases.
  • If the mass of the star is almost equal to that of the Sun, then it gradually cools down and changes into a sphere first, then cools down and finally turns into a small white body. goes. After some time this small body starts absorbing the light falling on it. Then it turns into a black hole not visible to the eye.
  • The change in light is visible from the motion of the stars or the galaxy. If the star is facing the observer, then its light will move towards the blue edge of the spectrum. But if the star is moving away from the observer, then its light will shift towards the narrow edge of the spectrum. This is called the Doppler effect.
  • The supernova star is the brightest star over 20. The brightest star as seen from Earth is the Cres Dang star.
  • The reason for the formation of black holes is the loss of energy of stars. Each star continuously emits large amounts of energy and continuously shrinks due to which the gravity increases. Due to this energy release, there comes a time when the energy ends and the stars stop flowing.
  • Stars appear white, but not all stars are white, some are orange, red or even blue.
  • Very hot stars are blue in color and cold stars red. The Sun is a yellow star. The temperature of the blue stars is from 27,750 ° C and that of the Sun is from 6000 ° C. So no astronaut can ever land on any star.
  • It takes three days for the spacecraft to reach the Moon. It takes several months to reach the sun. It may take thousands of years for a spacecraft to reach the nearest star. KM for such a long distance. Measuring in is a difficult problem. That's why scientists use the units of light years and parsecs to measure the distance to stars.
  • Light year is the distance that light travels three lakh km. Traveling at the speed of one second, it covers in one year - ie 30.857×1012 km.
  • In astronomy, a constellation is a group of stars visible in the sky. Throughout history, various civilizations have drawn imaginary lines between the stars in the sky to make them appear as figures, which they have given names. For example, in ancient India, there is a constellation named Mrigashirsha, which in Greek civilization is called Orion, which means "hunter". In ancient India, constellations were called Nakshatras. In modern-day astronomy, constellations are called groups of stars that are internationally agreed upon in the International Astronomical Union.

Quasars and Black Holes: 

Quasar: A quasar, which is an abbreviation for "quasi-stellar radio source", is a very bright active galactic nucleus. At the center of most large galaxies is a giant black hole, whose mass is equal to millions or millions of solar masses. Quasars and other active galactic nuclei have a gaseous accretion cycle around this black hole. When the gas from this accretion cycle falls into the black hole, it generates energy in the form of electromagnetic radiation, which is in the wavelengths of radio, infrared, light, ultraviolet, X-rays and gamma rays in the electromagnetic spectrum. The energy generated by quasars is terrifying and the luminosity of the most powerful quasars exceeds 1041 watts, thousands of times greater than that of large galaxies like our Kshirmarg.

Black Hole: A black hole or black hole is such an astronomical object with such a strong gravitational field that nothing, including light, can escape its pull. There is a boundary around the black hole called the event horizon in which objects can fall but cannot come out. It is called "black" (Krishna) because it also absorbs all the light falling on it and reflects nothing. It is just like an ideal black body in thermodynamics. Quantum analysis of black holes shows that they contain temperature and Hawking radiation.

What is Sun?

Sun or sun A star located in the center of the solar system, around which the earth and other components of the solar system revolve. The Sun is the largest body in our solar system and its diameter is about 13 lakh 10 thousand kilometers which is about 109 times more than the Earth. This mighty store of energy is a giant ball of gases, mainly hydrogen and helium. The Sun produces energy in its center by the process of nuclear fusion.

Only a small part of the energy released from the sun reaches the earth, of which 15 percent is reflected in space, 30 percent is used to vaporize the water and many of the energy is absorbed by the plants and seas. Its strong gravitational force keeps the Earth and other planets moving in different orbits towards it.

Some important facts related to Sun:

  • The distance from the Earth to the Sun is about 150 million km. Is. Its diameter is about 1,400,000 km. That is, 109 times the diameter of the Earth. Its gravity is 28 times greater than that of Earth.
  • The distance of the Sun from the center of the Milky Way is 32,000 light-years based on modern estimates. 250 km. The Sun takes 225 million years to complete one revolution around the center at an average speed per second. This period is called the cosmic year. The Sun also rotates on its axis like the Earth. The Sun is made of gases so it can rotate at different speeds at different latitudes. Its rotation period is about 24-26 days at the poles and 34-37 days at the equator. It is 300,000 times more massive than Earth.
  • The Sun is a supermass of glowing gases. It can be called a giant hydrogen bomb, because it produces a lot of heat and light by nuclear fusion. Life on earth is possible only with the light and heat coming from it. Its light takes 8 minutes 20 seconds to reach the earth.
  • The visible outer surface of the Sun is called the photosphere, whose temperature is about 6000 °C, but the temperature of the center is 15,000,000 °C.
  • Shining flames rise from the Sun's surface or photosphere, which are called solar flames. It is about 1000,000 km. reach height.

Structure of the sun

  • The photosphere is the visible radiant surface of the Sun.
  • The edge of the light sphere which is not radiant, its color is red, is called chromaticity.
  • The outer part of the sun (which is visible only during eclipses) aura.
  • The corona emits x-rays and the Earth is illuminated by this corona during a total solar eclipse.
  • When the temperature of a part of the Sun becomes less than that of other parts, it appears in the form of a spot, which is called a solar blur. The life span of this spot ranges from a few hours to a few weeks. Radio communication is interrupted after the solar blur persists for several days.

Dark spots also appear on the surface of the Sun. They are relatively colder than the surface temperature of the Sun (6000 °C), about 1500 °C. The life span of these spots ranges from a few hours to several weeks. The temperature of a large spot can range from 4000-5000°C. The spots are many times bigger than our Earth.

What is Solar System ?

The Solar System consists of the Sun and the celestial bodies, which are bound to each other in this system by the force of gravity. A group of celestial objects orbiting around a star that is not other stars, such as planets, dwarf planets, natural satellites, asteroids, meteors, comets and celestial dust. Our solar system is made up of our sun and its planetary system. These bodies include eight planets, their 172 known satellites, five dwarf planets, and billions of smaller bodies. These small objects include asteroids, icy Kuiper circles, comets, meteors, and interplanetary dust.

The four smaller inner planets of the solar system, Mercury, Venus, Earth and Mars, are called terrestrial planets, which are mainly made of stone and metal. And this includes the Asteroid Circle, the four giant outer gas giant planets, the Kuiper Circle and the Scattered Circle. The hypothetical Oort cloud may also exist beyond about a thousand times the distance from the charted regions. The flow of plasma from the Sun (solar wind) penetrates the solar system. It forms a bubble in the interstellar medium called the helio- mantle , which extends out from it to the middle of the scattered plate.

Contribution of India in the field of Astronomy:

There have been many great astronomers in ancient India who invented many astronomy principles and instruments, this led to great development of astronomy, in medieval times kings built space observatories and helped astronomers a lot. We are briefly describing some of the ancient astronomers of India and their contributions here.

Lagadha: - Thousand years before Christ, Lagadha composed a book named Vedanga Jyodish, in this text the time of celestial events has been described which was used to determine the time of social and religious functions. In this book the description of time, season, moon months, sun months etc. is given. In this book, 27 constellations, eclipses, together with planets, and 12 zodiac signs of astrology are mentioned.

Aryabhata :- The time of Aryabhata is 476 - 550 BC, Aryabhata composed two texts of astronomy, Aryabhatiya and Aryabhata Siddhanta, in these texts Aryabhata told for the first time that the earth rotates on its axis, and this is the reason. That all the stars are seen going towards the west, Aryabhata wrote that the earth is a sphere whose diameter is 39967 Km. It is Aryabhata who gave the reason for the moon to shine and said that it shines due to the light of the sun.

Brahmagupta: - The time period of Brahmagupta is 598-668 BC, he composed the book Brahmagupta Siddhanta, this text was translated into Arabic language in Baghdad and it had a great influence on Islamic mathematics and astronomy, in this text the day The beginning of time was told at 12 o'clock in the night, Brahmagupta wrote the theory that all things of mass are attracted towards the earth, Varahamihira: Varahamihira's time is considered to be 505 BC yesterday, Varahamihira wrote Indian, Greek, Egyptian and Roman astronomy He studied all this knowledge in one place in his book Pankasiddhantika. Bhaskar 1: - His time period 629 BC, he composed three texts Mahabhaskarya, Laghu Bhaskarya, and Arya Bhattiya Bhashya salt texts. Many principles of astronomy are described in these texts. Bhaskar II: - His time period is of 1114 AD, he was the head of the observatory of Ujjain, he composed the Siddhant Shiromani and Karanakutuhlah salt books. Apart from these, there were many other astronomers in India who made an unprecedented contribution to the development of astronomy by composing many new books, among them Sripati, Mahendra Suri, Neelkanth Somaya, Achyuta Pisarati.

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