Meaning of blue stellar object

blue' stel'lar ob'ject

Pronunciation: [key]
— Astron. Astron.
  1. any of a class of blue celestial objects, at one time thought to be stars, that do not emit appreciable radio waves. Abbr.: BSO
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.