An Etymological Dictionary of Astronomy and Astrophysics

The → Zeeman effect when observed at right angles to the orientation of the magnetic field. Un un-displaced line is observed along with a doublet, three lines in all, with the frequencies ν and
ν ± Δν. The two displaced components correspond to a plane of → polarization parallel to the external magnetic field and the un-displaced line to a plane of polarization perpendicular to this field. → longitudinal Zeeman effect.

See also: → transverse; → Zeeman effect.