Main sequence stars. Main sequence. In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness.
These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or "dwarf" stars.[1][2] After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward gravitational pressure from the overlying layers.
Main Sequence Stars. Credit: NASA The Sun The majority of stars in the galaxy, including our Sun, Sirius and Alpha Centauri A and B are all main sequence stars.
The Sun's relative longevity and stability have provided the conditions necessary for life to evolve here on Earth. Our understanding of the processes involved and characteristics of this key group of stars has progressed in parallel with our understanding of nuclear physics. Properties of Main Sequence Stars. Life's Little Mysteries. For millennia, people have looked up to the sky and wondered about celestial bodies.
The sparkling stars and fiery sun hold mystery and wonder. To astronomers, the sun is just another dying star, but to everyone else it’s a huge burning ball that gives heat, light, and life. So far so good. But what is it burning?