| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,756,516,471 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
Cepheid variable |
Also found in: Wikipedia, Hutchinson | 0.02 sec. |
Cepheid variableOne of a class of variable stars whose period of variation is closely related to its luminosity and is therefore useful in measuring the distances to clusters of stars and galaxies. Named for the prototype of this class found in the constellation Cepheus, classical Cepheids have periods from about 1.5 days to over 50 days and are Population I stars (see Populations I and II). The longer the period of such a star, the greater its natural brightness; this relationship was discovered in 1912 by the American astronomer Henrietta Leavitt (b. 1868—d. 1921). How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | ||
|---|---|---|---|
| The telescope's sharper vision will enable astronomers to image Cepheid variable stars, which serve as cosmic milemarkers, in galaxies more distant from Earth, providing a better estimate of the size and age of the universe, he says. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|