Stimatore Hertzsprung-Russell — Formula
## The Hertzsprung-Russell Diagram
The HR diagram plots stellar luminosity against temperature. For main-sequence stars, hotter stars are larger and more luminous.
### Empirical Approximation
Radius: **R / R_sun ≈ (T / T_sun)^0.8**
Luminosity from Stefan-Boltzmann: **L / L_sun = (R/R_sun)² × (T/T_sun)⁴**
These are rough main-sequence estimates. Giants, supergiants, and white dwarfs fall off the main sequence.
The HR diagram plots stellar luminosity against temperature. For main-sequence stars, hotter stars are larger and more luminous.
### Empirical Approximation
Radius: **R / R_sun ≈ (T / T_sun)^0.8**
Luminosity from Stefan-Boltzmann: **L / L_sun = (R/R_sun)² × (T/T_sun)⁴**
These are rough main-sequence estimates. Giants, supergiants, and white dwarfs fall off the main sequence.
Esempio Risolto
A star with T = 10 000 K (A-type).
- T/T_sun = 10000/5778 = 1.731
- R/R_sun ≈ 1.731^0.8 ≈ 1.562
- L/L_sun = 1.562² × 1.731⁴ = 2.440 × 8.975 ≈ 21.9
- About 22 solar luminosities.