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The XStar N-body Solver

XStar is a Unix program that simulates the movement of stars. It starts by putting a bunch of stars on the screen, and then it lets the inter-body gravitational forces move the stars around. The result is a lot of neat wandering paths, as the stars interact and collide.

Figuring out what paths these stars should take is called the "N-Body Problem", and when there are more than 3 stars involved (N>3), this can be a very hard problem to solve. XStar is just a "toy" N-body solver, but it generates a lot of pretty pictures and gives you an idea of how stars interact. "Real" N-body solvers have to work with many thousands, or even millions of stars, while XStar works with dozens.

Along with the program, there is a fairly large document that explains the N-Body problem in a fair amount of detail. It doesn't get into the gory details of the "real" N-body solvers, but it does give you an overview of the techniques they use.


The source code for XStar (version 2.2) can be obtained as xstar.tar.gz (231k) or xstar.tar (829k)

The introductory text on the N-body Problem that comes with the source code to XStar can be obtained separately as n-body.ps.gz (157k), n-body.ps (498k), n-body.pdf (292k), or as web pages (57 pages).


Here are some other useful links that I found while researching the n-body problem:

Starlab: A Software Environment for Collisional Stellar Dynamics
A Portable Parallel Particle Program.
Amara's Recap of Particle Simulation Methods
Scientific Applications for Linux: Physics and Astronomy

While I'm not an expert, I believe the information on this page is correct. Please send suggestions and corrections to the webmaster.
This web site runs on 100% Open Source Software. This web page was last changed on 05/15/2004 at 15:06:26.