star, a feature known as ultraviolet excess.Usually members of the Milky Way's halo, they frequently have high space velocities relative to the Sun.

Cool subdwarfs of spectral type L and T exist, such as ULAS J131610.28+075553.0 with spectral type sdT6.5.

Subclasses of cool subdwarfs are as following:; cool subdwarf: Examples: Kapteyn's Star (sdM1), GJ 1062 (sdM2.5); extreme