February 13, 2006

Building a Counterrotating Protoplanetary Disk

TOP VIEW: A huge star-forming region is rotating globally in the direction shown by the white arrow. This large region can give birth to multiple stellar systems.

MIDDLE VIEW: A detailed view inside the large star-forming region shows three protostars forming as the region collapses. The collapse process is chaotic and can cause eddies, allowing newly-forming stars to rotate in different directions and at different speeds, as shown by the arrows.

BOTTOM VIEW: One protostellar cloud collapses further into a disk-like structure that rotates counter-clockwise (white arrows) about the newly-formed protostar. In addition, the protostar siphons off material from a second, passing protostellar cloud rotating in the opposite direction. Because of this, the outer part of the disk rotates clockwise (yellow arrows). Eventually, planets will form from the material in this disk, with the outer planets orbiting the star in the opposite direction from the inner planets.

CREDIT: Bill Saxton, NRAO/AUI/NSF

Copyright © 2009 Associated Universities, Inc.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.