The Hertzsprung-Russell diagram maps stellar luminosity against effective temperature (or spectral class).
Main sequence, giants, and white dwarfs occupy distinct regions and encode stellar structure/evolution status.
At fixed luminosity, hotter stars are smaller; at fixed temperature, larger stars are more luminous.
Higher mass stars burn fuel rapidly due to steep luminosity dependence.
Massive stars evolve faster despite larger fuel reservoirs.
Low/intermediate masses tend toward white dwarfs; higher masses can produce neutron stars/black holes after core collapse pathways.
Ionization balance links spectra to atmospheric temperature and electron pressure.
Use calibrated relationships (e.g., Wilson-Bappu style trends) with caution regarding scatter and metallicity dependence.
Track motion in HR space from protostar through giant phases to compact remnant outcomes.
Switch to the Simulation tab to explore the same relationships numerically under this unit topic.
Compare low-mass and high-mass tracks on the HR plane and identify divergence points.
Estimate relative main-sequence lifetimes for 1, 5, and 15 solar-mass stars.
Map initial mass bins to expected final states and discuss physical uncertainties.
Use the quiz and tutor to justify each phase transition with core-physics arguments.
CSV columns: sapid, student_name, age_myr, phase, log10_teff, log10_lum, teff_k, lum_lsun, radius_rsun, metallicity_z, mass_msun, timestamp_iso. JSON includes full metadata and full evolutionary log. The Python script uses matplotlib to reproduce an H-R track from the exported data.
| Age (Myr) | Phase | log10(Teff) | log10(L) | Teff (K) | L/L☉ | R/R☉ |
|---|---|---|---|---|---|---|
| No data yet — run the simulation with "Log data" checked. | ||||||
This interactive module targets Unit 3 of PHYS4022P. Students connect H-R diagram structure, stellar lifetimes, and final evolutionary outcomes through computational exploration.
References used to ensure scientific accuracy of this module. Open-access links are provided where available.