This HST image revealed for the first time the inner regions of the disk of material that surrounds the star Beta Pictoris. From the ground, this inner part of the disk is impossible to observe because of the glare from the star itself. The disk is made up of many microscopic grains of material, possibly a mixture of water ice and sand-like substances. This dust is lit up by the star. At the center of the disk is a clear zone and astronomers have speculated that this zone is occupied by a planetary system, similar to our own solar system. A planetary system could have formed from the dust in this part of the disk and would act to clear away any remaining material.
That idea is supported by evidence from this HST image. The inner edge of disk is warped, in the same way that a CD would be warped if someone serted a pencil in the central hole and twisted it. The lower version of the image has been further processed with false color to highlight the warp. Beta Pictoris is estimated to be 200 million years old, but a warp such as this could only last for about one million years before being flattened out - unless something is pulling on the disk and distorting it out of shape. A possible and plausible explanation is that a large planet, or a system of planets, is responsible for the warping action. It is not possible to see the suspected planet(s) directly because it (or they) are too close to the star, and perhaps a billion times fainter.
Attention was first focused on Beta Pictoris when
it was found to emit infrared radiation strongly. Optical observations
then showed there is a disk around the star with a diameter about ten times
the size of Pluto's orbit around the Sun.
Camera: WPC2 in PC mode
Technical Information: Composite of three
images taken through filters at 555, 675 and 814 nm (green, red and infrared).
Credit: C. Burrows (STScl and ESA), J.
Krist (STScI), and NASA
