O star
O star
[′ō ‚stär] (astronomy)
A star of spectral type O, a massive, very hot blue star with a surface temperature of at least 35,000 K (63,000°F), and a spectrum in which lines of singly ionized helium are prominent.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.