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,rotation)
Further reading:

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