Calculateur de Température Stellaire
Calculez la température de surface d'une étoile.
Température effective
5,778 K
Effective Temperature vs B-V Colour Index
Formule
## Stellar Temperature from Colour The B-V colour index measures the difference in brightness between blue (B) and visual (V) filters. Bluer (hotter) stars have lower B-V. ### Ballesteros Formula **T = 4600 × (1/(0.92(B-V)+1.7) + 1/(0.92(B-V)+0.62))** K The Sun has B-V ≈ 0.65, giving T ≈ 5780 K.
Exemple Résolu
The Sun: B-V = 0.65.
- 010.92 × 0.65 = 0.598
- 021/(0.598+1.7) + 1/(0.598+0.62) = 1/2.298 + 1/1.218
- 03= 0.4352 + 0.8210 = 1.2562
- 04T = 4600 × 1.2562 ≈ 5778 K
Questions Fréquentes
What B-V values correspond to what star types?
B-V < 0 is for hot blue O/B stars (>10 000 K). B-V ~ 0.6-0.8 is for Sun-like G stars. B-V > 1.4 is for cool red M dwarfs (<3500 K).
How is B-V measured?
By observing a star through two standard filters (B and V) and computing the magnitude difference: B-V = m_B - m_V.
Is this formula exact?
It is an empirical fit accurate to about 100 K for most main-sequence stars. Heavily reddened or peculiar stars may deviate.