Alcyone is a star system in the constellation Taurus. Approximately 440 light years from Earth,  it is the brightest star in the Pleiades open cluster.  The primary component, Alcyone A, is a blue-white B-type giant with an apparent magnitude of +2.85. It is an eclipsing binary, and the two components have a separation of about the distance from the Sun to Jupiter. It is an emission star and a high rotational velocity of some 215 km/s has created a disk of gases flung into orbit around the star from its equator.

Alcyone A

In the Star Trek: The Next Generation episode "Haven", the Alcyones were a spacefaring civilization that destroyed what was believed, by the Federation, to be the last Tarellian plague vessel. It was later discovered that the ship they destroyed was not the last plague ship, following the discovery of another such vessel in the Beta Cassius system by the Enterprise-D.

Tarellian plague shio