Who is regarded as one of the most important astronomers of all time, and invented a morphological classification scheme for galaxies?
Hubble sequence The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often known colloquially as the Hubble tuning fork diagram because of the shape in which it is traditionally represented.
C.C.L. Gregory Christopher Clive Langton Gregory (13 May 1892 – 24 November 1964) was a British astronomer, who established the University of London Observatory.