She and colleagues confirm for an earlier period than ever before that the shapes and colors of these extremely distant young galaxies fit the visual classification system introduced in 1926 by Edwin Hubble and known as the Hubble Sequence.
Lee explained that this was a key question: When, and over what timescale did the Hubble Sequence form?
But these galaxies evolved into the regular galaxies that make up the Hubble Sequence
This set of galaxy types is known as the Hubble sequence.
The real challenge for those of us studying the origin of galaxies is to try to understand the steps by which the Hubble sequence came into being," says Ellis.
The astronomers show that the Hubble sequence six billion years ago was very different from the one that astronomers see today.
A team of European astronomers led by Francois Hammer of the Observatoire de Paris has, for the first time, completed a census of galaxy types at two different points in the Universe's history in effect, creating two Hubble sequences - that help explain how galaxies form.
Graham (Astrophysics Institute of the Canary Islands), even the visible-light Hubble sequence
itself turns out to be "something of an optical illusion.
Those plates led the famous astronomer to define what we now call the Hubble sequence.
As it turns out, one is hard-pressed to put the rich diversity of galaxy forms in the HDF images into the orderly bins of the Hubble sequence.
But as we shall see, bars may play a significant role in the architecture of the Hubble sequence
The Hubble sequence
sorts galaxy forms into ellipticals, spirals, barred spirals, and irregulars (S&T: May 1992, page 515).