Astrophysics (Index)About

ultracool dwarf

(ultra-cool dwarf)
(star or brown dwarf cooler than M7 class)

The term ultracool dwarf has been used for spectral class M⁠7 or later (cooler) stars, such as L-type star, T-type star, Y-type star, and/or brown dwarfs. An example is TRAPPIST-1. The term was coined for the convenience of studies relating to this combination of classes.

(star type)
Further reading:

Referenced by pages:
Two Micron All-sky Survey (2MASS)