Star Colour-Temperature Calculator Formula
Understand the math behind the star colour-temperature calculator. Each variable explained with a worked example.
Formulas Used
Peak Wavelength
peak_nm = 2.8978e6 / temperatureApproximate B-V
bv_estimate = -3.684 * log10(temperature) + 14.551Variables
| Variable | Description | Default |
|---|---|---|
temperature | Surface Temperature(K) | 5778 |
How It Works
Star Colour and Temperature
A star's colour is determined by its surface temperature. Hotter stars appear blue-white; cooler stars appear orange-red.
Peak Wavelength (Wien's Law)
lambda_max = 2.8978e6 / T (nm)
Approximate B-V from Temperature
B-V ≈ -3.684 log10(T) + 14.551
This empirical fit works reasonably for main-sequence stars between 3000 and 30 000 K.
Worked Example
A blue star at 10 000 K.
temperature = 10000
- 01Peak = 2 897 800 / 10000 = 289.8 nm (ultraviolet)
- 02B-V ≈ -3.684 × log10(10000) + 14.551
- 03= -3.684 × 4 + 14.551 = -0.185
- 04Negative B-V: more blue than visual light, appears blue-white.
Ready to run the numbers?
Open Star Colour-Temperature Calculator