Share this Article on Facebook Twitter Submit this article to Reddit Give this article a thumbs-up on StumbleUpon

globular cluster

globular cluster

A Dictionary of Astronomy | 1997 | Copyright

globular cluster A roughly spherical group of old stars in the halo of a galaxy. Globular clusters contain from tens of thousands to millions of stars, and have diameters of 100–300 l.y. At the centre of the cluster, where most stars are concentrated, the density may be over 250 stars per cubic light year. About 150 globular clusters are known in our Galaxy, travelling on highly elongated orbits around the galactic centre. They are very old, about 1010 years, having formed early in the history of the Galaxy. Stars in globular clusters are members of Population II, with a low content of heavy elements (only a few per cent of the solar value), although a few show values approaching that of the Sun. On the Hertzsprung–Russell diagram of a globular cluster, the main sequence and the giant branch are smoothly joined via a subgiant branch; also conspicuous is an asymptotic giant branch and a horizontal branch, punctuated by an instability strip containing RR Lyrae variables. Globular clusters are found around all large galaxies, but are most abundant around giant elliptical galaxies. Some galaxies, particularly those that have undergone recent mergers, contain large numbers of young globular clusters.
Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"globular cluster." A Dictionary of Astronomy. 1997. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>.

"globular cluster." A Dictionary of Astronomy. 1997. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O80-globularcluster.html

"globular cluster." A Dictionary of Astronomy. 1997. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-globularcluster.html

Learn more about citation styles

globular cluster

World Encyclopedia | 2005 | Copyright

globular cluster Near-spherical cluster of very old stars in the halo of our galaxy and others. Globular clusters contain anything from 100,000 to several million stars, concentrated so tightly near the centre that they cannot be separately distinguished by ground-based telescopes.
Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"globular cluster." World Encyclopedia. 2005. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>.

"globular cluster." World Encyclopedia. 2005. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O142-globularcluster.html

"globular cluster." World Encyclopedia. 2005. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-globularcluster.html

Learn more about citation styles

globular cluster

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

globular cluster see star cluster .

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"globular cluster." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>.

"globular cluster." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1E1-X-globular.html

"globular cluster." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-X-globular.html

Learn more about citation styles

Free newspaper and magazine articles

Pictures from Google Image Search

Click to see an enlarged picture
Click to see an enlarged picture
Click to see an enlarged picture

See more pictures of globular cluster

Related topics

  Be the first to connect related topics with this page!