A subclass of the C-class asteroids. Its members have low albedos (0.03–0.07), and a featureless reflectance spectrum, flat to slightly bluish over the wavelength range 0.3–1.1 μm. F-class asteroids are distinguished from class C by having a weak to non-existent ultraviolet absorption feature. Members of this class include (142) Polana, diameter 55 km, and (213) Lilaea, diameter 83 km.
Subjects: Astronomy and Astrophysics.