What sort of star is the Sun?
The Sun is a main sequence star of the G type. The On the HR diagram, 'main sequence' component of the term relates to the fact that the Sun is at a point in its existence where hydrogen to helium conversion is the predominant fuel source. The stars in this phase are on the Hertzsprung-Russell (HR) diagram's main sequence. This graph plots the absolute magnitudes of stars against their surface temperatures.
The Sun is a 4.5 billion-year-old yellow dwarf star in the heart of our solar system, a hot glowing ball of hydrogen and helium. It is approximately 93 million miles (150 million kilometers) from Earth and is the solitary star in our solar system. Life as we know it could not exist on our home planet without the Sun's energy.
From our perspective on Earth, the Sun seems to be a constant source of light and heat in the sky. However, the Sun is a dynamic star that is continually changing and emitting energy into space. Heliophysics is the science of studying the Sun and its effects on the rest of the solar system.
