A galaxy classification grid that better recognises early-type galaxy
  morphology
  A modified galaxy classification scheme for local galaxies is presented. It
builds upon the Aitken-Jeans nebula sequence, by expanding the Jeans-Hubble
tuning fork diagram, which itself contained key ingredients from Curtis and
Reynolds. The two-dimensional grid of galaxy morphological types presented
here, with elements from de Vaucouleurs' three-dimensional classification
volume, has an increased emphasis on the often overlooked bars and continua of
disc sizes in early-type galaxies - features not fully captured by past tuning
forks, tridents, or combs. The grid encompasses nuclear discs in elliptical (E)
galaxies, intermediate-scale discs in ellicular (ES) galaxies, and large-scale
discs in lenticular (S0) galaxies, while the E4-E7 class is made redundant
given that these galaxies are lenticular galaxies. Today, these disc structures
continue to be neglected, or surprise researchers, perhaps partly due to our
indoctrination to galaxy morphology through the tuning fork diagram. To better
understand the past and present classification schemes - whose origins reside
in solar/planetary formation models - a holistic overview is given. This
provides due credit to some of the lesser known pioneers, presents some
rationale for the grid, and reveals the incremental nature of, and some of the
lesser known connections in, the field of galaxy morphology.
