Friday, 03rd September 2010

   home     about     authors     news     physics forums         RSS feed     sitemap     privacy     physics archives     free magazines
Stellar Energy Generation and Nucleosynthesis - Science Articles Science Articles

Physics Articles

folder add to favorites
 folder make home page

blank
Astronomy/Cosmology
 Education
 How Stuff Works
 Mathematics
 Mystics/Pseudo Science
 Other Sciences
 Physics
 Technology
 Theoretical Physics

Our Newsletter



Subscribe
Unsubscribe
  Voting Poll

We will most likely find life on...
Titan
Mars
Europa
Callisto
Other


  Featured Book

  Physics Tip


Viscosity
The property of a liquid that makes it resist flow or any change in the arrangement of its molecules. The higher the viscosity, the "thicker" a liquid seems.
 

  Physics Quote


It is impossible to trap modern physics into predicting anything with perfect determinism because it deals with probabilities from the outset.
    Sir Arthur Eddington (1882 - 1944)
 

 
 
 

Stellar Energy Generation and Nucleosynthesis
Author: Philip Mathew
 Added: 03/21/2003
 Type: Tutorial
 Viewed: 10575 time(s)
 Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10Average visitor rating of 7.8/10
How would you rate this article:    Bad Good   Go » 

  

Page I

Introduction: The evolution of stellar objects is inherently caused by the chemical composition of the star.  Internally, thermonuclear reactions leading to the formation of complex atoms lead to a change in chemical composition which in turn will affect the evolutionary position of a star.

Energy Generation: Energy generation is made possible by proton-proton reactions.  In a proton-proton chain, two protons colliding with a minimum energy of 8 X 106 K will lead to the formation of a heavy hydrogen nucleus that will consist of a proton and neutron.  Furthermore, a positron (the electron's anti-particle) and a neutrino will break away.  The positron will collide with an electron and the two particles will annihilate one another (as particle physics dictates) to form two gamma rays.  A hydrogen atom will then crash into another proton to form helium and a gamma ray.

Another form of energy generation in stars is from the carbon-nitrogen-oxygen cycle (mercifully shortened to CNO cycle).  The CNO cycle is vital and predominate in more massive starts of one solar mass or greater.  The minimum energy for a greater CNO output compared to proton-proton output is roughly 20 X 106 K.  The CNO cycle is initiated by the conversion of a radioactive nitrogen isotope which is formed by the collision of a proton and carbon nucleus.  The nitrogen becomes a carbon isotope by emitting a positron and a neutron.  Proton bombardment will lead to the gamma ray emission and the conversion into a stable nucleus of nitrogen.  Further proton bombardment will convert the nitrogen nucleus into radioactive oxygen, which will decay into a nitrogen nucleus, a positron and a neutron.  The nitrogen isotope will then split into a C-12 and a He-4 after a collision with a proton.  The carbon in a CNO cycle serves as the catalyst since it remains unchanged in the CNO cycle.


Article Pages:  1 | 2 | Next »  
                          


  Article Comments   Add Comment | View All (0)

    There are currently no comments for this article.


Advanced Search
recent Recent Science Articles



Recent Articles function is down for the time being as we update the script. Stay tuned for a better and more updated news rotator.

links Science Links


Physics Post is just one of many quality physics sites on the web. Contact us if you feel you've found a diamond in the rough.

Astronomy and Cosmology

Chemistry

Credit Counselors

General Discussion

Philosophy

Securities Brokerage

Technology


 

Physics Songs

 
We provide daily science articles, physics articles and science news.
Our mission is to create a wide array of basic and advanced science articles for you to read and expand your science knowledge. Content here is not reviewed for accuracy, we rely on the expertise of the authors and the peer review in the comments section. If you want to submit a physics or science article please contact us.
All content © 2010, Physics Post. .