Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Barred Spiral Galaxy and Rotation
Name: Randy
Status: educator
Grade: 9-12
Location: MA
Country: N/A
Date: 10/12/2005

What kind of mass distribution would be required to make the bar in a barred spiral galaxy rotate as a unit? Does it in fact rotate as a unit? Like a rigid body?

Very timely!! An article: "Ripples in a Galactic Pond" in the October 2005 issue of Scientific American addresses your question in detail. The article also cites a number of Internet and print sources for further exploration. The dynamics of galaxies is not simple and is not fully understood. To say much more is way beyond what can be done in a format like NEWTON BBS.

Vince Calder

Click here to return to the Astronomy Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory