Taurus II

Taurus II might refer to two completely distinct planets:

Taurus II (Murasaki 312)

Taurus II is a planet located within the Murasaki 312 quasar-like phenomenon.

In 2267, the shuttlecraft Galileo crash-landed on Taurus II while attempting to investigate the Murasaki effect. The crew, under the command of Lieutenant Commander Spock made first contact with the Taureans, and lost crew members Latimer and Gaetano while on the surface.

The inhabitants of Taurus II are order 480-G anthropoids, similar to lifeforms discovered on Hanson's Planet but much larger, ten to twelve feet in height. They are at approximately a stone-age level of technology, slightly less advanced than a "Folsom culture". (TOS: "The Galileo Seven")

Taurus II (Taurean system)

Taurus II is planet located in the Taurean system, in a sector largely unexplored by the Federation until the late-23rd century.

As late as 2119, an alien race settled on Taurus II when their homeworld began to die. They built for themselves an advanced civilization, including a temple and numerous other architectural wonders.

Unfortunately, these new inhabitants did not know that the planet drains humanoid energy. The women's bodies were able to develop a glandular secretion that enabled them to survive and to manipulate certain areas of the male's brains to influence their emotions, ultimately draining the men. This caused the men to weaken and eventually die. The females realized that in order to survive, they must revitalize every 27 years, as they became eternal prisoners on Taurus II. They were neither capable of aging, dying or bearing children. They revitalized themselves by means of summoning male crewmembers of starships from as far as twenty light years away.

In 2269, the USS Enterprise was investigating several disappearances within range of Taurus II when they fell victim to the Taurean summons. (TAS: "The Lorelei Signal")