Skip to main content

Astronomy (thesaurus)

Search from vocabulary

Concept information

Preferred term

spiral arm  

Definition

  • Spiral arms are regions of stars that extend from the center of barred and unbarred spiral galaxies. These long, thin regions resemble a spiral and thus give spiral galaxies their name. Naturally, different classifications of spiral galaxies have distinct arm-structures. Sc and SBc galaxies, for instance, have very "loose" arms, whereas Sa and SBa galaxies have tightly wrapped arms (with reference to the Hubble sequence). Either way, spiral arms contain many young, blue stars (due to the high mass density and the high rate of star formation), which make the arms so bright. (Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/wiki/Spiral_galaxy#Spiral_arms)

Broader concept

In other languages

URI

http://data.loterre.fr/ark:/67375/MDL-K92W68LN-3

Download this concept: