N-body problem, n-body,
many-body problem, astronomy, gravity, gravitational, ordinary
differential equation, ODE, numerical analysis, numerical integration,
integration, source code, calculus, source code
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
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
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
The introductory text on the N-body
Problem that comes with the source code to XStar can
be obtained separately as
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
Parallel Particle Program.
Recap of Particle Simulation Methods
Scientific Applications for Linux: Physics and Astronomy