Stars are plotted on a 3D Hertzsprung-Russell diagram: X = surface temperature (reversed, hot→left), Y = luminosity (log scale), Z = time axis tracing the evolutionary track.
L ∝ M^3.5 (main sequence)
t_MS ≈ 10 Gyr × (M/M☉)^-2.5
R_s = 2GM/c² (Schwarzschild radius)
- Star mass — sets initial luminosity, temperature and lifetime; also decides the final remnant (white dwarf, neutron star, or black hole).
- Evolution speed — scales simulated time so you can watch a whole stellar lifetime in seconds.
- Evolve / Reset — starts or restarts the track from the zero-age main sequence.
- Trigger Merger — spawns a compact companion that spirals in and merges, radiating a gravitational-wave ripple through spacetime.
- Dark Matter Halo — toggles a faint particle halo representing the unseen mass inferred from galactic rotation curves.
Real application: mass–luminosity–lifetime relations let astronomers estimate a star's age and predict supernova risk from its spectral class alone.