William Wilson Morgan

From Wikipedia, the free encyclopedia

William Wilson Morgan (January 3, 1906 – June 21, 1994) was an American astronomer.

The principal theme in Morgan's work was the study of stellar and galaxy classification. Along with Philip Keenan he developed the MK system for the classification of stars through their spectra. He also developed several galaxy morphological classification systems, including the first systems to use the physical properties of galaxies, as opposed to simple eye-ball estimates favoured by Edwin Hubble. He invented the now widely used classification cD for massive galaxies in the centres of clusters.

He worked at Yerkes Observatory. Along with Donald Osterbrock and Stewart Sharpless, he used distance measurements of O and B type stars to show the existence of spiral arms in the Milky Way Galaxy.