An Etymological Dictionary of Astronomy and Astrophysics

In the → Hubble classification, galaxies on the left part of the → Hubble sequence.
Early-type galaxies tend to have redder colors, higher average surface brightnesses, and lower → neutral hydrogen content than → late-type galaxies. This terminology is based on the obsolete and erroneous idea that → elliptical and → lenticular galaxies might be evolutionary precursors to → spiral and → barred spiral
galaxies.

See also: → early; → type; → galaxy.