A
lenticular galaxy is a type of
galaxy which is intermediate between an
elliptical galaxy and a
spiral galaxy in
galaxy morphological classification schemes. Lenticular galaxies are
disc galaxies (like spiral galaxies) which have used up or lost most of their
interstellar matter and therefore have very little ongoing
star formation. They may, however, retain significant dust in their disks. As a result, they consist mainly of aging stars (like elliptical galaxies). Because of their ill-defined
spiral arms, if they are inclined face-on it is often difficult to distinguish between them and elliptical galaxies. Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features, scaling relations and both can be considered early type galaxies which are passively evolving, at least in the local universe.