Are Pictures of Extrasolar Planets in the Offing? (Astronomy)
The first image of a planet orbiting a star other than the sun may be only a year away, thanks to a powerful image-sharpening technique called adaptive optics.
Because stars are thousands to billions of times brighter than their planets, even a planet several times as massive as Jupiter is not easy to discern against the glare of its stellar parent. That's why researchers have so far inferred the existence of the 80 or so known extrasolar planets only indirectly, by the wobble they induce in the motion of the stars they orbit.
Adaptive optics now promises to provide the first direct visual evidence of extrasolar planets. The technique relies on a computer-controlled system that subtly reshapes a telescope's mirror hundreds of times a second to compensate for the blurring caused by Earth's turbulent atmosphere (SN: 3/4/00, p. 156). Over the past few years, astronomers have installed such systems on some of the world's largest telescopes, including the 10-meter Keck II and the 8.1-m Gemini North on Mauna Kea in Hawaii.
The extraordinary resolution afforded by the technology can clearly separate a young planet from its parent star, say Ray Jaywardhana of the University of California, Berkeley and Michael Liu of the University of Hawaii in Honolulu. Researchers don't yet have an image of a bona fide extrasolar planet--or if they do, they're not ready to unveil it. …