Edwin Hubble

NASA and ESA space telescope (launched 1990)

American astronomer (1889–1953)

galaxy having a number of arms of younger stars that spiral out from the centre containing older ones

observation in physical cosmology

type of galaxy

astronomical observatory in Los Angeles County, California

morphological classification scheme for galaxies invented by Edwin Hubble

system for categorizing galaxies based on how they look like

astronomy dealing with objects outside the Milky Way

variation in the Hubble constant