The researchers suggest that there are two processes at work. First, carbon monoxide in the disk may be destroyed by ultraviolet light from the central star and other nearby stars. Second, the molecules in the cooler centre may condense onto dusty particles. Molecular hydrogen is both more resistant to destruction by ultraviolet light and unlikely to condense. The group looks to NASA's Space Infrared Telescope Facility, to be launched in 2002, to provide new data and reveal just what life is like within the planetary nurseries of young stars.
New observations indicate that such planetary nurseries last twice as long as previously thought.
An object at least 17 times the size of Jupiter, discovered orbiting a Sun-like star, has astronomers scratching their heads.