Stars are spherical or spherical-like objects composed of hot gaseous matter that emit light. It takes about eight minutes for the light of the Sun, a star close to Earth, to reach Earth. The scales of stars are extremely diverse, ranging from less than a few kilometres to more than 109 kilometres;The mass distribution of the vast majority of stars is 01 In the 10 solar mass range, their atmospheric chemistry is similar to that of the sun, consisting mainly of hydrogen and helium. The heat and light of a star are due to the high temperature of its interior, which can reach millions or even hundreds of millions of degrees, and complex reactions are undergoing inside it, radiating huge amounts of energy and matter outward. Stars are formed by the condensation of nebulae and are always in constant motion and change. Because of its distance, the ancients called it a "star". Most of the stars in the night sky are stars, and there are more than 6,000 of them that can be observed with the naked eye. A staggering number of stars can be observed using telescopes, even in the hundreds of thousands or even millions.
The lifetime of a star varies according to its volume and mass. Our Sun is a typical yellow dwarf star with an estimated lifespan of about 10 billion years. However, red giants only have a lifespan of a few million years. Supermassive stars, on the other hand, will run out of nuclear fuel and collapse into black holes in just a million years. Overall, the lifetime of a star is affected by both the rate of nuclear reactions and the size of its mass.
In the 17th century, Newton proposed the idea that diffuse matter would coalesce into stars under the influence of gravity. Astronomers have observed that interstellar space is filled with molecular clouds of gas and dust, and that the denser parts are denser under gravitational pull. When the gravitational pull is strong enough to resist the pressure, the gas cloud will rapidly shrink, forming a solar system-sized disk of air and dust, and the matter will gradually fall onto the protostar. In this process, gravity heats up the protostar, and when the temperature rises to 10 million degrees Celsius and triggers a thermonuclear reaction, the star is born. The mass of a star is in the range of 0between 1 100 solar masses. Too little mass to trigger a nuclear reaction, while too much mass will disintegrate due to too high radiation pressure. In recent years, infrared astronomical satellites have detected thousands of stars in the process of formation.
Stars, as treasures of astronomy, directly affect the structure and evolution of the universe and the functioning of ecosystems. Issues such as the birth, structure, brightness, temperature, and observable visual threshold of stars have always been the focus of scientific research, and we need to continue to dig deeper to solve these mysteries. At the same time, in recent years, the discovery of infrared astronomical satellites has revealed that more than 10 million stars are in the formation stage. Looking ahead, astronomers will be focusing on the trend of star change and **.