How old is the Sun?

 

The sun. Credit: https://lovethenightsky.com/

The sun is a medium-sized star located at the center of the solar system. It is the primary source of light and heat for the planets and other objects in the solar system. The sun is made up of a ball of gas, primarily hydrogen and helium, that is held together by its own gravity. At the core of the sun, the extreme pressure and temperature cause the hydrogen atoms to fuse together and form helium, a process known as nuclear fusion. This fusion releases a tremendous amount of energy in the form of light and heat, which is then radiated outwards from the sun's surface.

The sun is about 4.6 billion years old, which means that it has been around for about 4.6 billion years. It is thought to have formed at the same time as the rest of the solar system, which is believed to have formed about 4.6 billion years ago. The sun is a main-sequence star, which means that it is currently in the stable part of its life cycle, converting hydrogen into helium through nuclear fusion in its core. Main-sequence stars like the sun are expected to remain in this stable phase for a significant portion of their lifetime, typically several billion years.

The sun is expected to remain in this stable phase for another 5 billion years or so before it begins to evolve into a red giant star. As the sun continues to fuse hydrogen into helium in its core, the core will eventually become depleted of hydrogen. When this happens, the sun will begin to contract and become denser, causing the temperature and pressure at its core to increase. This will trigger the fusion of helium into heavier elements, such as carbon and oxygen, and the sun will start to expand and cool, eventually becoming a red giant star.