Popper, Daniel M. Department of Astronomy, University of California, Los Angeles, California.
- Effects of stellar evolution
- Stellar mass and luminosity determination
- Evolution of close binary systems
- Links to Primary Literature
- Additional Readings
The relation, observed or predicted by theory, between the quantity of matter a star contains (its mass) and the amount of energy generated in its interior (its luminosity). Because of the great sensitivity of the rate of energy production in a stellar interior to the mass of the star, the mass–luminosity relation provides an important test of theories of stellar interiors. This predicted relation is a corollary of the more general principle that if a star is in equilibrium—it is neither expanding nor contracting—all its other properties depend only on its mass and the distribution of chemical elements within it. For a family of stars with different masses but with the same mixture of chemical elements uniformly distributed throughout the stellar volumes, there should be a unique mass–luminosity relation. The observed relation, obtained from binary stars for which masses and luminosities can be observationally evaluated, is shown in the illustration. The majority of stars placed on such a plot are found along this relation, called the main sequence, and it implies that all stars begin their lives with roughly the same chemical composition. It conforms reasonably well to theory. It was this agreement that showed the pioneering studies of stellar structure by A. S. Eddington in the 1920s to be on a sound basis. See also: Binary star; Star
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information