ScienceHutch · Interactive astronomy
The life cycle of a star
Explore how a Sun-like star is born, shines, evolves, and leaves behind a white dwarf.
Stable hydrogen fusion
Main sequence
Hydrogen fuses into helium in the core. Our Sun is in this long-lived stage today.
What's happening physically?
Pressure supported by fusion-generated heat balances inward gravity in hydrostatic equilibrium. The proton–proton chain dominates in Sun-like stars.
Did you know?
The Sun is about 4.6 billion years old.
Why stellar mass matters
A star's initial mass strongly influences its lifetime and eventual fate. Change the mass to explore the difference.
Lower- or intermediate-mass star
Following giant-star phases, stars in this broad range generally leave white dwarfs. Details vary substantially with mass.
Approximate main-sequence lifetime 10.0 billion yearsIllustrative estimate: t ≈ 10¹⁰ (M/M☉)⁻²·⁵ years, where M☉ is the Sun's mass. This approximation is especially unreliable at the lowest and highest masses; it is not a stellar evolution simulation.
Check your understanding
Massive stars have more fuel, but their energy output and fuel consumption increase disproportionately with mass, shortening their main-sequence lifetimes.
Schematic educational experience. The six-stage timeline describes a star of roughly the Sun's mass; more massive stars follow different late stages. Durations and temperatures are approximate and depend on stellar mass and composition.