Robert Williams

Robert Eugene Williams (October 14, 1940) is an American astronomer who served as the director of the Space Telescope Science Institute (STScI) from 1993 to 1998, and the president of the International Astronomical Union (IAU) from 2009 to 2012.

Education Williams studied at the University of California, Berkeley receiving a bachelor of science degree in 1962.

Career After receiving his doctorate in 1965 Williams was employed at the University of Arizona until 1983. the NASA Distinguished Public Service Medal in 1999, and the 2016 Karl Schwarzschild Medal.

A member of the American Academy of Arts & Sciences, Williams' research specialties cover nebulae, novae, and emission-line spectroscopy and analysis. He is an advocate for science education and has lectured internationally on the discoveries of the Hubble Space Telescope. In 1996, Williams made the controversial decision to offer the director's discretionary time on the Hubble Space Telescope to two competing teams using distant supernovae to determine the universe's expansion rate accurately. The two teams independently found that the universe's expansion was accelerating due to a previously unknown energy source. The leaders of the two teams were awarded the 2011 Nobel Prize in Physics for the discovery.

In 2015 Williams retired and was appointed emeritus professor of STScI.