Admin and Founder of The Secrets of the Universe and former intern at Indian Institute of Astrophysics, Bangalore, I am a science student pursuing Master’s in Physics from India. I love to study and write about Stellar Astrophysics, Relativity& Quantum Mechanics.
The ancients worshiped the Sun for it was the source of energy. The Sun is the reason behind our existence. Everything revolves around the Sun in our little family called solar system. It is majestic. It is the core of our solar system. Today we know more about the Sun than our ancients ever did. With the advancement in simulations and other technology, we have an idea about what lies in that massive ball of fire we see. Let us now discuss 10 amazing facts about Sun.
10. How Big Is Our Sun?
If we compare Sun with the size of the planets, it is quite big. About 1.3 Million Earths can fit inside the Sun. The mass of Sun is 2 million trillion trillion Kg. That is 99.96% the mass of the entire solar system. These numbers might make you think that the Sun is a beast. But, in reality, Sun is just an average star in the Universe. There are giants that are even bigger. The biggest of all, UY Scuti, can encapsulate 5.1 billion Suns in it.
9. How Far Is The Sun?
The Sun is approximately 150 million Km away. This distance is known as 1 Astronomical Unit (AU). Light from the Sun takes 500 seconds to reach us. Now this means that if Sun blacks out at some moment, we won't know it for 500 seconds. Also, if Sun suddenly disappears (which it won't, of course), the Earth will keep on going around in its orbit for 500 seconds after which it will fly off along the tangent of its elliptical orbit.
8. How Hot Is The Sun
The solar core is burning at 15 million K. This is the temperature than can host a full scale hydrogen fusion. As we go away from the burning core, the temperature starts decreasing and reaches 5,900 K at the surface.
7. The Corona Mystery
The corona is the outermost layer of the solar atmosphere as shown in the Sun. The surface of Sun, also known as the, photosphere has temperature of 6,000 K. However as we move away from the Sun's surface, temperature stars increasing anomalously. The temperature of Corona is a few million degrees. This is against the law of thermodynamics according to which heat can only flow from hot system to cold system. Here it appears to flow from in opposite fashion. This is the solar corona heating problem. It is one of the most important unsolved problem in plasma and solar physics.
6. What Type of Star Is Sun?
One of the most important facts about Sun is its classification. There are about a trillion trillion stars in the universe. In Astrophysics, there is a classification scheme known as the Yerkes classification. Stars are classified according to their electromagnetic spectrum. There are two main factors used in this classification: The surface temperature and the surface gravity. Since the Sun has an average surface temperature of 5,900 K, it is a G type main sequence star or a G V star. Such stars are nick named as yellow dwarfs.
5. The Source of Sun's Energy
The source of stellar energy was a complete mystery even in 1920s. It was one of the greatest Astrophysicist, Arthur Eddington, who correctly hypothesized in his paper (The Internal Constitution of Stars), that the source of stellar energy is nuclear fusion. The temperature in the core of the Sun is about 15 million K. Sun produces energy by fusing hydrogen into helium in its core by the nuclear reaction called PP chain. In this reaction, 4 hydrogen atoms fuse to form 1 helium atom thereby releasing 26.7 MeV of energy per fusion reaction.
4. What's Inside The Sun?
The internal structure of Sun can be divided into three main categories: The core, the radiation zone and the convection zone. The radiation zone lies just next to the core. Here the energy from the central core is transported via radiation. Next to it lies the convection zone. As the name suggests, the plasma is in the form of convection currents. The plasma gets heated, rises up, comes to the surface, cools down and falls back. Imagine heating a pot of water. The radiation and convection zone are separated by Tachocline.
3. The Magnetic Field of Sun
When magnetic energy is released by the Sun during magnetic storms, solar flares occur which we see on Earth as sunspots. Sunspots are dark areas on the Sun’s surface caused by magnetic variations. The reason they appear dark is due to their temperature being much lower than surrounding areas.
2. How Old Is The Sun?
This is one of the most fascinating facts about Sun. Our Sun is approximately 5 billion years old. It has been fusing hydrogen into helium in its core for the past 5 billion years. There is enough hydrogen in the core of the Sun to support fusion for another 5 billion years. Thus the Sun will live for a little more than 10 billion years.
1. The Ultimate Fate of Sun
After it has consumed all its hydrogen, the happy days of the Sun will be over. So far, the Sun has been in a perfect hydrostatic equilibrium. This means that force of gravity which tends to collapse the star is balanced by the gas pressure from the nuclear reaction in the core. The Sun will ultimately lose this balance. It will go on the fuse heavier elements till carbon but it does not have the potential to host a full scale carbon fusion. Hence the Sun will collapse into a white dwarf star, which will have size equivalent to that of Earth. It will be very dense. A teaspoonful of its material can outweigh the heaviest object on Earth.
These were the 10 amazing facts about Sun. Share with your friends and family!