- A 2012 paper that suggests a new classification system -first proposed by the Canadian astronomer Sidney van den Bergh- for lenticular and dwarf spheroidal galaxies (S0a-S0b-S0c-dSph) that parallels the Hubble sequence for spirals and irregulars (Sa-Sb-Sc-Im) reinforces this idea showing how the spiral-irregular sequence is very similar to this new one for lenticulars and dwarf elliptical.
- Lenticular galaxies are sometimes called "armless spiral galaxies." Lenticular galaxies have a central bulge, but no spiral arms. If the central bulge is not very bright, it can be very difficult to tell the difference between a lenticular galaxy and an E0 galaxy
- Just like spiral galaxies, some lenticular galaxies have a bar. They are called "barred lenticular galaxies" and are denoted SB0. Normal lenticular galaxies are denoted S0.