World Library  
Flag as Inappropriate
Email this Article

Stellar dynamics

Article Id: WHEBN0000456270
Reproduction Date:

Title: Stellar dynamics  
Author: World Heritage Encyclopedia
Language: English
Subject: Star, Stellar physics, Subrahmanyan Chandrasekhar, Computational astrophysics, Astronomical Calculation Institute (Heidelberg University)
Collection: Gravitation, Stellar Astronomy, Stellar Dynamics
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Stellar dynamics

Stellar dynamics is the branch of astrophysics which describes in a statistical way the collective motions of stars subject to their mutual gravity. The essential difference from celestial mechanics is that each star contributes more or less equally to the total gravitational field, whereas in celestial mechanics the pull of a massive body dominates any satellite orbits.[1] Stellar dynamics is usually concerned with the more global, statistical properties of several orbits rather than with the specific data on the positions and velocities of individual orbits.[2] The motion of stars in a galaxy or in a globular cluster are principally determined by the average distribution of the other, distant stars, and little influenced by the nearest stars.

Recently, simulations of the N-body problem have provided an addition to the older analytical methods, enabling researchers to study systems that are otherwise intractable.

Contents

  • Introduction 1
  • Recommended Reading 2
  • See also 3
  • External links 4
  • Bibliography 5

Introduction

The long range of gravity and the slow "relaxation" of stellar systems prevent the use of the (conventional) methods of statistical physics,[3] as stellar dynamical orbits tend to be much more irregular and chaotic than celestial mechanical orbits.[4]

The "relaxation" of stars is the process deflecting the individual trajectories of stars from the one they would have if the distribution of matter was perfectly smooth. The "2-body relaxation" is induced by the individual star-star interactions, while the "violent relaxation" is induced by a large collective variation of the stellar system shape.

There is a mathematical undercurrent to stellar dynamics; the key physical theories, classical analytical mechanics, Newtonian gravity and (statistical) thermodynamics on the one hand are closely related to the mathematical branches of dynamical systems and ergodic theory (itself having major connections to DS theory) respectively. The possibility of gravitational interactions and collisions also lead to a treatment of mathematical scattering theory. As such a number of stellar dynamicists are also mathematicians by training.

Recommended Reading

  • Dynamics and Evolution of Galactic Nuclei, D. Merritt (2013). Princeton University Press.
  • Galactic Dynamics, J. Binney and S. Tremaine (2008). Princeton University Press.
  • Gravitational N-Body Simulations: Tools and Algorithms, S. Aarseth (2003). Cambridge University Press.
  • Principles of Stellar Dynamics, S. Chandrasekhar (1960). Dover.

See also

External links

  • Part II Stellar Dynamics and Structure of Galaxies, Cambridge tripos.

Bibliography

  1. ^ Will C Saslaw: "Encyclopedia of Astronomy and Astrophysics: Stellar Dynamics.". Pg 1. Accessed 26 January 2012
  2. ^ Will C Saslaw: Work cited
  3. ^ Will C Saslaw: Work cited
  4. ^ Will C Saslaw: Work cited


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.