Stellar Lifespan Race (2D)

Launch a Star

Mass 1.0 M☉

Time speed 50M yr/s

Race Status

Elapsed time

0 yr

Still on main seq.

0 / 0

Fastest burner

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Longest-lived

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Roster

How it works

Every star here obeys two real main-sequence scaling laws relating mass to how it lives and dies:

L / L☉ = (M / M☉)^3.5
t_MS = 10^10 × (M / M☉)^-2.5  years
R / R☉ ≈ (M / M☉)^0.8
T_eff = 5778K × (L / R²)^0.25

Luminosity rises with roughly the 3.5th power of mass, but the fuel supply only grows linearly with mass — so lifetime falls off as mass^-2.5. A 20 M☉ blue star is ~2.4 million times more luminous than the Sun but burns through its core hydrogen in only a few million years. A 0.3 M☉ red dwarf is dim but will still be fusing hydrogen long after the Sun is gone.

Mass slider + Launch — adds a new star to the lane, racing at the chosen mass (0.1–40 M☉).
Time speed — how many simulated years pass per real second; higher speeds let low-mass stars' multi-billion-year lifetimes finish in view.
Drag the track to pan and scroll to zoom — each star's lane position is its % of main-sequence lifetime elapsed, so zooming in reveals how far apart massive and low-mass stars really are early in the race.
When a star exhausts its core hydrogen it swells into a red giant, then collapses to its end state: a white dwarf (M < 8 M☉), a neutron star (8–25 M☉), or a black hole (M > 25 M☉), following the Chandrasekhar / neutron-degeneracy mass limits.

🔵 hot / massive · 🔴 cool / low-mass
⚪ white dwarf · 🟣 neutron star · ⚫ black hole

drag to pan · scroll to zoom