Stellar Classification Calculator

Determine spectral class from surface temperature

Surface Temperature (K)

Formula

OBAFGKM classification based on surface temperature

What is spectral classification?

Stars are classified O B A F G K M from hottest to coolest. The Sun is a G2 star at 5778 K.

What does the number after the letter mean?

It is a subclass from 0 (hotter) to 9 (cooler) within each spectral type.

Free star luminosity calculator. Calculate stellar luminosity from absolute magnitude or from radius and temperature.

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