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Star Temperature Calculator

Estimate the surface temperature of a star based on its peak emission wavelength using Wien's Law.

400nm (Blue) 700nm (Red)
Surface Temperature
-- K

Wien's Displacement Law

Wien's Law states that the blackbody radiation curve for different temperatures peaks at a wavelength inversely proportional to the temperature. In simpler terms, hotter stars appear bluer, while cooler stars appear redder.

Understanding Star Colors

The Sun peaks at around 500nm (greenish-yellow), which corresponds to a surface temperature of about 5,800 Kelvin. A very hot star like Rigel (12,000 K) peaks in the ultraviolet, making it appear blue-white to our eyes.

Frequently Asked Questions (FAQ)

Are there any green stars?

No. Although some stars peak in the green part of the spectrum, they emit light across all visible wavelengths, which our eyes perceive as white or yellowish-white.

What is the temperature of the coldest stars?

Red dwarfs can have temperatures as low as 2,500 Kelvin, while brown dwarfs can be even cooler, sometimes below 500 Kelvin.