the main sequence

The main sequence is a stage in a star's life cycle where it spends most of its existence, including our Sun. During this phase, stars fuse hydrogen into helium in their cores, releasing energy that produces light and heat. This process balances the inward pull of gravity with the outward pressure from the energy produced. Main sequence stars vary in size, temperature, and brightness; larger stars burn hotter and faster, while smaller stars live much longer. Eventually, when they exhaust their hydrogen, they evolve into different forms, such as red giants or supernovae, depending on their mass.