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Protoplanetary Disks III

October 6, 2010

HD 100546 is just 10 million years old. It's so young, in fact, that it's still encircled by the "leftovers" from its formation -- a wide, thin disk of gas and dust. Planets may be taking shape inside the disk -- and at least one giant planet might already have been born there.

Astronomers are studying the disk to learn more about the processes that give birth to planets. An international team, for example, has examined the system with a space telescope called Herschel. It was launched last year to study the universe at infrared wavelengths.

Infrared is produced by relatively cool objects -- like the disks of gas and dust around newborn stars. Different infrared wavelengths reveal details about the disk's composition and structure.

In the case of HD 100546, infrared observations have revealed that the disk is many times wider than the realm of the planets in our own solar system. And there's a gap in the disk fairly close to the star -- possibly swept clean by a giant planet.

Both the inner and outer parts of the disk contain a mineral that's a common building block of planets. But the grains in the outer part of the disk are a puzzler. Either they formed in the inner portion of the disk and worked their way outward before the gap was cleared, or they formed in a different process from what astronomers expect. Either way, these grains of dust around a newborn star will help us learn about how all planets are born.


Script by Damond Benningfield, Copyright 2010

Today's program was made possible in part by the NASA Science Mission Directorate.

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