The → turbulence phenomenon involving relatively smaller
physical volumes compared to → macroturbulence.
In stellar atmospheres, it is a bulk gas motion with a characteristic size
less than the local photon → mean free path.
Microturbulence is one of the most significant mechanisms that can cause
→ line broadening in the stellar spectrum.
The presence of microturbulence de-saturates strong lines and increases their
→ equivalent widths. Microturbulence in
→ hot stars brings about gas motions with velocities
0-20 km s-1. A physical connection may exist between
microturbulence in hot star atmospheres and a subsurface
→ iron convection zone. Microturbulence may also
be at the origin of → wind clumping in hot stars.
See also: → micro-; → turbulence.
