Mtype

Mtype, often written as M-type, is a designation used in several scientific and technical contexts to denote a class labeled with the letter M. There is no single, universal definition for Mtype; its meaning depends on the field and the classification scheme in use.

In astronomy, M-type is most commonly encountered as a spectral class. M-type stars are cool, red stars with temperatures typically around 2400 to 3700 kelvin. They are among the most common stellar types in the Milky Way and include many red dwarfs. The spectra of M-type stars show strong molecular bands, such as titanium oxide, and they have relatively low masses and luminosities. Because of their abundance and long lifetimes, M-type stars are frequent targets in studies of exoplanets and galactic evolution.

In asteroid taxonomy, M-type designates a class of asteroids believed to be largely metallic, composed mainly of nickel-iron. M-type asteroids tend to have relatively high albedo compared with other asteroid classes and are thought to represent fragments from the cores of differentiated bodies. They are concentrated mainly in the middle regions of the asteroid belt, though they appear in various orbital families.

Outside of astronomy, the term M-type may appear as a label in other classification schemes or as part of product or project names. Because Mtype is not tied to a single standard, its precise meaning should be inferred from the relevant disciplinary context.