Stimatore Classe Spettrale — Formula
## Spectral Classification (OBAFGKM)
Stars are classified by surface temperature into spectral types:
| Class | Temperature Range | Colour |
|-------|------------------|--------|
| O | > 30 000 K | Blue |
| B | 10 000 - 30 000 K | Blue-white |
| A | 7 500 - 10 000 K | White |
| F | 6 000 - 7 500 K | Yellow-white |
| G | 5 200 - 6 000 K | Yellow |
| K | 3 700 - 5 200 K | Orange |
| M | < 3 700 K | Red |
The output code: 7=O, 6=B, 5=A, 4=F, 3=G, 2=K, 1=M.
Stars are classified by surface temperature into spectral types:
| Class | Temperature Range | Colour |
|-------|------------------|--------|
| O | > 30 000 K | Blue |
| B | 10 000 - 30 000 K | Blue-white |
| A | 7 500 - 10 000 K | White |
| F | 6 000 - 7 500 K | Yellow-white |
| G | 5 200 - 6 000 K | Yellow |
| K | 3 700 - 5 200 K | Orange |
| M | < 3 700 K | Red |
The output code: 7=O, 6=B, 5=A, 4=F, 3=G, 2=K, 1=M.
Esempio Risolto
The Sun at 5778 K.
- 5778 K falls between 5200 and 6000 K.
- Spectral class: G (code 3)
- Peak wavelength: 2897800 / 5778 = 501.5 nm (green)
- The Sun is a G2V star.