A decade ago, finding planets orbiting other stars was the stuff of science fiction. But that has since changed. Since 1995, the planet-hunting team led by R. Paul Butler of the Carnegie Institution of Washington and Geoffrey Marcy of the University of California at Berkeley has discovered 38 of the 53 known extrasolar planets. The duo's finds include the only planet thus far found to transit a host star, two sub-Saturn mass planets, and, as just announced, a multiple-planet system that may alter our current definition of the term planet.
For their unprecedented accomplishments, the National Academy of Sciences (NAS) announced yesterday that the co-investigators will be awarded the prestigious Henry Draper Medal on April 30 during the 138th meeting of the NAS.
The NAS awards the Draper Medal every four years to those who have made a significant contribution to astronomical physics. It was established through the Draper Fund and was first awarded in 1886. Butler and Marcy will receive the medal "for their pioneering investigations of planets orbiting other stars via high-precision radial velocities."
They will join the ranks of other laudable astronomers including George Ellery Hale, Arthur Eddington, Harlow Shapley, Horace Babcock, and the team of Penzias and Wilson.
The celestial detectives are leaders of a team engaged in a multi-year research project to look for planets around 1,100 stars that are within 300 light-years of Earth. Some of the planets they have thus far detected have challenged existing theories on planetary formation.
Butler's work focuses on improving the precision for measuring stellar Doppler velocities -- a technique that detects telltale stellar wobbles indicating an orbiting planet. He designed and built the Iodine absorption cell system at the Lick Observatory of the University of California, Santa Cruz, which resulted in the discovery of six of the first eight extrasolar planets. This instrument is now the de facto standard for precision Doppler studies.
Marcy and Butler together conceived this novel technique for detecting the stellar wobble and deducing from it the mass and orbit of its companion planet. After some eight years of hard work, they announced their first planet discoveries in 1995, shortly after a Swiss team reported the first tentative detection of an extrasolar planet.
Since then, Marcy, Butler, and their colleagues have continued observations at the Lick telescope, and have extended their planet search to the more sensitive Keck telescopes in Hawaii, which are operated by a consortium of the University of California and Caltech. To view stars in the Southern Hemisphere, the team uses the Anglo-Australian Observatories and will use Carnegie's Magellan telescopes in Chile as they become operational.
By 2010, the team hopes to have completed a "planetary census" of nearby stars. They will be able to tell what percentage of stars have planets, how many planetary systems are like our own solar system, and how many types of planetary systems exist.
Their work is supported by NASA, the National Science Foundation and Sun Microsystems. Other team members include Debra Fischer of UC Berkeley and Steve Vogt of UC Santa Cruz. More information about the team's work can be found at this URL.
[Contact: Tina McDowell, Robert Sanders]
12-Jan-2001
