Gerard de Vaucouleurs was born on 25 April 1918 in Paris, France. He received his undergraduate degree in 1939 and, following World War II, his graduate degree in 1949, both from the University of Paris, where he did his work in the Sorbonne Physics Research Laboratory and the Institute of Astrophysics. His dissertation involved research on mo¡lecular (Rayleigh) scattering of light in gases and liquids. He subsequently lived in England (1950-51), then moved to Australia, where he also earned a DSc degree from the Australian National University in 1957, for research in molecular physics, optics, photography, astronomy and astrophysics. This degree reflected his real passion: astronomy, which occupied most of his research career. De Vaucouleurs moved to the US in 1957. He worked at both Lowell and Harvard College observatories before joining the faculty of the University of Texas at Austin in 1960.

De Vaucouleurs was an observer who was meticulous with the data he collected and had an extraordinary knowledge of galaxies, recognizing hundreds of them by sight. His research was characterized by a respect and even reverence for the data and a reluctance to produce grand theories.

Among his many contributions, he was the first person to calculate the cosmic background light due to galaxies (1949). He established (1953-56) the reality of the Local Supercluster (or Local Supergalaxy) and the effect of its mass concentration on the motion of nearby galaxies (1958-64). He developed standard parameters to describe the luminosity distributions and angular diameters of galaxies. He discovered the r1'' law of the luminosity distribution of elliptical galaxies (1948) and was the first to use the general technique of photometric decomposition of spirals into bulge and disk components. He discovered (1953-56) the spiral structure and, with Frank J. Kerr, the rotation of the Large and Small Magellanic Clouds. With Allan Sandage, he developed (1956-59) a three-dimensional scheme, a personal revision of Hubble's original galaxy classification system. He showed that the main dimension in this scheme correlated well with measured global parameters such as bulge-to-disk ratio, integrated colors, hydrogen mass-to-light ratios and mean surface bright¡nesses. With Antoinette de Vaucouleurs, his first wife, he made the first quantitative analysis (1957) of the composite radiation of a stellar system (the bar of the Large Magellanic Cloud). He also discovered secondary or "nuclear" bars in barred galaxies (1974) and recognized the importance of rings and especially pseudorings in spiral galaxy morphology. He was the first to propose that the Milky Way is a barred spiral with a broken inner pseudoring (1963-69) and, with William D. Pence, derived the first quantitative two-dimensional model of the Milky Way (1978-79). His work on the Local Supercluster and the Milky Way bar was so controversial that it was more than two decades before either idea became generally accepted.

Gerard de Vaucouleurs is probably best known for his extensive work on the cosmic distance scale and for his production of three reference catalogs of bright galaxies in 1964, 1976 and 1991. The hallmark of the reference catalogs was homogenization of data from widely different sources, so that the catalogs would be astrophysically useful databases. Much of the data on morphology, magnitudes, colors and radial velocities that went into these catalogs was obtained by de Vaucouleurs himself and his coworkers over many years. Using data in the reference catalogs, de Vaucouleurs was able to develop new distance indicators and refine many others that were already known. He had a unique philosophy on distance matters of "spreading the risks," that is, not putting all the weight on a few distance indicators but applying as many different and independent techniques as possible to check for scale and zero point errors. He favored a large value of the Hubble constant and a short timescale for the cosmological expansion. He wrote many detailed publications highlighting his methods and in particular distinguishing them from those of other leading distance scale workers at the time.

excerpted from APRIL 1996 PHYSICS TODAY