Wednesday, February 10, 1999 Published at 08:42 GMT
Hubble spies planet 'nurseries'
The dark band is the disc viewed side on
Is this a picture of planets in the making?
It was taken by Nasa's Hubble Space Telescope. It shows a huge disc of dust and gas encircling a young star in the constellation Taurus 450 light-years away. The disc is viewed edge-on.
The material in the disc is so thick it mostly obscures the light coming from the star and appears as a dark band across the centre of the image.
It is a lucky snapshot. Circumstellar disks are normally very difficult to see, largely because the glare of the central star overpowers the feeble reflected light from the disc.
More than a dozen possible extrasolar planets have been discovered (though not imaged) over the past few years, but astronomers lack detailed pictures of environments around newborn stars where planets form.
"While the existence of these discs has been known from prior infrared and radio observations, the Hubble images reveal important new details such as a disc's size, shape, thickness, and orientation," said Deborah Padgett of Caltech's Infrared Processing and Analysis Center, Pasadena, California.
Deborah Padgett's group used Hubble's Near-Infrared Camera and Multi-Object Spectrometer (Nicmos) to peer through obscuring dust clouds surrounding six stars. Evidence for dusty disks was found in all of them, in the form of dark bands or dust lanes crossing bright areas around each star. The presumed discs have sizes 8 to 16 times the diameter of Neptune's orbit.
Two other Hubble research groups report similar discoveries. One team from NASA's Jet Propulsion Laboratory has found the first example of an edge-on disk in a young double star system. Their work suggests that planet formation should be possible even in such binary star systems.