Concept

Spectral Classification (OBAFGKM)

Stars sorted by surface temperature.

The Harvard system classifying stars from hottest to coolest as O, B, A, F, G, K, M, with subdivisions 0–9. The Sun is type G2V.

Overview

The Harvard system classifying stars from hottest to coolest as O, B, A, F, G, K, M, with subdivisions 0–9. The Sun is type G2V.

See also