The Sun at 5772 K

Plate 68 speaks for itself: “The Sun is white.”

The Physics

The Sun's surface radiates roughly as a 5772 K blackbody. Its spectrum peaks in the blue-green by wavelength, but spread over all visible colours it looks white from space.

λ_max = b / T

• λ_max: peak wavelength, m
• b: Wien displacement constant 2.897771955×10⁻³ m K
• T: temperature, K

Peak at λ_max = b/T ≈ 502 nm. Over all wavelengths it looks white.

Honest caveat: The peak position depends on whether you plot per wavelength or per frequency; per frequency it sits in the near infrared.

Sources

• IAU 2015 Resolution B3.
• CODATA 2018.

On the poster

Plate 068, “The Sun at 5772 K”: the pixel-art plate with its slogan “The Sun is white.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.