Searching for Shadows of Other Earths; September 2000; Scientific American Magazine; by Laurance R. Doyle, Hans-Jorg Deeg, Timothy M. Brown, side bar by Ray Jayawardhana; 8 Page(s)
No one has ever seen a planet outside our solar system. But in November of last year two astronomers saw the next best thing: its shadow. David Charbonneau, a graduate student at Harvard University, was analyzing the brightness of the sunlike star HD 209458 using data taken earlier, when he had been working with one of us (Brown). At nearly the same time, Tennessee State University astronomer Greg Henry was independently observing the same star.
It is an unassuming star, without even a proper name. But it has one claim to fame: around it orbits a planet with a mass at least two thirds that of Jupiter. Or so astronomers thought. The planet had only been inferred indirectly by the wobbles it induced in the star. Charbonneau and Henry sought confirmation by a different technique. Might it be possible, they asked, for the planet to pass in front of the star, across our line of sight, and temporarily block some of the starlight?