Dust Grain

Grains of carbon and silicate ~0.1-1.0 μm in size. Dust grains are a major component of the interstellar medium. Dust blocks visible light causing interstellar extinction and scatters incident starlight, particularly blue light (which has a wavelength comparable to the dust grain’s size), causing reddening. Cooling of interstellar gas and dust clouds occurs by infrared emission from the dust.

Some or all content above used with permission from J. H. Wittke.