By Ron Cowen
Eleven years ago, David Charbonneau was a new graduate student at Harvard University’s astronomy department, eager to explore the birth of the universe. “Then I learned of the incredible first discoveries that had just been announced in exoplanets,” he recalls. Those objects, the first planets found outside the solar system, prompted Charbonneau to drop the Big Bang like a hot potato. He’s been hunting for exoplanets ever since.
Yet the orbs that piqued the imagination of Charbonneau and so many other astronomers in the mid-1990s were then little more than phantoms. Too small to be seen, each planet revealed its presence only because its gravitational pull made its parent star wobble a little. Astronomers could ascertain just two basic properties of each of these elusive planets: a minimum value for its mass and the time it takes to orbit its star.