(spectral type of star cooler than an M-type star)
An L-type star (L) is of the L-class
(L spectral class), cooler than M-type stars,
radiating mainly in the infrared.
They are generally dwarf stars (L dwarf), i.e., not a giant star.
They have metal hydride and alkalide metal absorption lines.
Some are considered brown dwarfs, never burning hydrogen,
but it is possible for main sequence stars to fall in this class.
(star type,spectral type)
brown dwarf (BD)
Spectroscopic Properties of Cool Stars (SPOCS)
TW Hydrae association (TWA)