Astrophysics (Index)About

Be star

(early star with Balmer emission lines)

A Be star is an early star, generally a B-type star, with emission lines such as hydrogen Balmer lines. Such an A-type star might be referred to as a Be star, using the classification loosely, or alternately, might be termed an Ae star. Similarly for an O-type star (Oe star). Current theory is that Be stars are rotating rapidly, and heating a circumstellar disk of gas ejected by the rotation (a decretion disk). Many show overlaid H-alpha emission and absorption lines, each with considerable line broadening, the former indicating the rotation of the disk and the latter, the rotation of the star.

A B[e] star and a Be star are different types, the former being a B-type star with forbidden emission lines.


(star type,Balmer series)
Further reading:
http://en.wikipedia.org/wiki/Be_star
http://en.wikipedia.org/wiki/B(e)_star
http://www.astrosurf.com/buil/us/bestar.htm
https://www-n.oca.eu/stee/page1/page3/page3.html

Referenced by pages:
chemically peculiar star (CP star)
decretion disk
shell star (sh)

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