An Etymological Dictionary of Astronomy and Astrophysics

A special type of carbonaceous → interstellar dust grains
with a size ranging from 10 to 150 Å and consisting of tens to hundreds of atoms. In contrast to → big grains, VSGs are not in → thermal equilibrium. They can be heated to very high temperatures (~ 1000 K) by the absorption of a single photon. It is thought that VSGs are clusters of → PAH.

See also: → very; → small; → grain.