Murasaki 312 is a fictitious astronomical object in the Star Trek universe. It is mentioned in two episodes: "The Galileo Seven" (set in the year 2267) from the original series and "Data's Day" (set in 2367) from Next Generation. In both it is described as a "quasar" or "quasar-like" phenomenon.
Captain James T. Kirk of the USS Enterprise was under standing orders to investigate formations similar to Murasaki 312. Consequently he delayed the Enterprise from a medical supply mission to Makus III, and sent the shuttlecraft Galileo to survey the formation. Sensor readings from the Enterprise indicated a "negative ion concentration" of 1.64 × 109, radiation wavelength of 370 angstroms, and harmonics "upward along the entire spectrum." The phenomenon is said to have ionized an entire sector, including four solar systems. It is located near the planet Taurus II.
Studies of the Murasaki effect were still underway a century later when the Enterprise-D gathered information on this object using long-range sensors.
The real science of Murasaki 312
The Mursaki phenomenon has the appearance of a diffuse emission nebula. The greenish coloration could be due, for example, to the recombination of doubly ionized oxygen [O III], which is often gives a blue-green tinge to real nebulae. However, radiation from the Mursaki object is said to have a wavelength of 370 angstroms – in the ultraviolet part of the spectrum.
Whatever Murasaki 312 is, it cannot be a true quasar, which is an immensely powerful and remote extragalactic object (the bright core of an active galaxy). The description "quasar-like" could be interpreted as meaning a microquasar, of which a number are known in our galaxy. But the appearance of Murasaki 312 is not at all what would be expected of a microquasar. Perhaps the phenomenon is something still beyond our ken, awaiting discovery in the 22nd century.