The sun is the only star whose surface details can be observed. What we directly observe is the atmosphere of the sun, which is divided into three layers from the inside out: the photosphere, the chromosphere and the corona. Although the sun is a stable, balanced and luminous gas ball on the whole, its atmosphere is in local violent motion. Such as: the appearance of sunspots, the change of prominence, the outbreak of flares and so on. The occurrence of solar activity is closely related to the solar magnetic field. The space around the sun is also full of violent gas and magnetic field ejected by the sun.
The Sun is a prime star with medium mass and high energy, which is located in the Milky Way, about 65,438+00 parsec from the galactic center, and about 8 parsec to the north of galactic plane. The diameter of the sun is 1392 thousand kilometers, which is 109 times that of the earth. The volume of the sun is 14 1 100 million cubic kilometers, which is10.3 million times that of the earth. The mass of the sun is nearly 200 billion tons, which is 330 thousand times that of the earth. It concentrates 99.87% of the mass of the solar system and is the absolute supreme "king".
The sun is a hot gas planet without a solid star or core. From the center to the edge, the sun can be divided into nuclear reaction area, radiation zone, convection zone and atmosphere. 99% of solar energy is generated by thermonuclear reaction in central nuclear reaction area. The density and temperature in the center of the sun are extremely high, and there is a thermonuclear reaction in which hydrogen condenses into helium, which can last for 65.438+0 billion years, so the sun is currently in middle age. The main components of the solar atmosphere are hydrogen (about 7 1 mass%) and helium (about 27 mass%).
For human beings, the brilliant sun is undoubtedly the most important celestial body in the universe. Everything grows on the sun. Without the sun, there would be no various life phenomena on the earth, and of course there would be no such intelligent creatures as human beings. The sun gives people light and heat, brings the cycle of day and night and seasons, affects the change of the earth's temperature, and provides various forms of energy for life on earth.
The sun has been transmitting light and heat to the earth. With sunlight, plants on the earth can carry out photosynthesis. The leaves of most plants are green because they contain chlorophyll. Chlorophyll can only use the energy of sunlight to synthesize various substances. This process is called photosynthesis. According to calculation, green plants all over the world can produce about 400 million tons of protein, carbohydrates and fat every day, and at the same time release nearly 500 million tons of oxygen into the air, providing sufficient food and oxygen for people and animals.
In human history, the sun has always been the object of worship by many people. The ancestors of the Chinese nation regarded their ancestor Yan Di as the sun god. In ancient Greek mythology, the sun god was the son of Zeus (the king of gods).
The sun, an awesome planet, how long will its life last? The age of the sun is about 4.6 billion years and it can continue to burn for about 5 billion years. In the last stage of its existence, helium in the sun will be transformed into heavy elements, and the volume of the sun will begin to expand until it engulfs the earth. After the red giant stage of 1 100 million years, the sun will suddenly collapse into a white dwarf-the last stage of the existence of all stars. After trillions of years, it will eventually completely cool down and then slowly disappear into the darkness.