OB association

OB association

See association.

OB association

[¦ō′bē ə‚sō·sē′ā·shən]
(astronomy)
A grouping of very young, very hot massive stars of spectral types O and B that has not had time to disperse.
References in periodicals archive ?
Zeta ([zeta]) Persei is the most southerly bright star of Perseus--and also the brightest star in the Zeta Persei OB Association. Other hot stars of spectral type O and B in the association, which is estimated to have a remarkably young age of only about 1 million years, include Omicron ([omicron]), Xi ([xi]), 40, X, and AG Persei.
New research by astrophysicists from the University of Rochester focused on stars in the north part of the constellation, known as Upper Scorpius, which is a part of the Scorpius-Centaurus OB association, one of the best studied groups of young stars and a benchmark sample for investigating the early lives of stars and the evolution of their planet-spawning disks.
About 35 of the thousands of stars in this group, known as the Scorpius-Centaurus (Sco-Cen) OB association, weigh several times as much as the sun.
While moving at random and not gravitationally bound, the hot, young stars of spectral type O and B in Scorpius, Centaurus, and Crux have astrophysical importance as the nearest OB association to our Sun.
Antares is the brightest member of the Scorpius-Centaurus OB Association, the nearest such large grouping of hot, young stars of spectral class O and B.
THE MILKY WAY in Puppis and Vela harbors many young blue stars and fine open clusters that are part of the Vela OB association. They're well known to Southern Hemisphere observers but less familiar to stargazers farther north.
The cluster lies about 1,600 light-years away--consistent with many of the stars in the giant Scorpius-Centaurus OB association, a large grouping of massive stars that have a common age and proper motion.
The Scorpius-Centaurus OB association is the nearest region of significant ongoing star formation.
This hot, blue-white supergiant is believed to be part of the Scorpius-Centaurus OB Association ("Sco-Cen"), a large region of recent and ongoing star formation that counts among its members many of the brighter stars in tonight's sky.
While both are members of the sprawling Scorpius-Centaurus OB association, a grouping of hot young stars in our local spiral arm that were born around the same time (several million years ago), Upsilon is about 180 light-years closer to us.
At a distance of 600 light-years, Antares is probably the most famous member of the Scorpius-Centaurus OB Association (see the June issue, page 90).
Considered to be a member of the Scorpius-Centaurus OB Association (June issue, page 90), 2.3-magnitude Alpha Lupi is some 550 light-years distant.