memory alpha

Mizar, also known as Zeta Ursae Majoris or 79 Ursae Majoris, was an inhabited planetary system in the Alpha Quadrant. In Earth's night sky, it appeared as a second-magnitude star.

This star system was just over a light year from the Alcor system.

Components

Stellar system

This was a quaternary star system. It was organized into a pair of binary star systems. The four stars – Mizar (the proper name for Zeta Ursae Majoris Aa), Zeta Ursae Majoris Ab, Zeta Ursae Majoris Ba, and Zeta Ursae Majoris Bb – were all A-type dwarfs. (ENT: "Cold Front")

Planetary system

There were at least two planets in this system. In the system's habitable zone, there was Mizar II, which was the Mizarian homeworld. (TNG: "Allegiance")

History

Location of Mizar labeled on a star chart (2256)

Location of Mizar labeled on a star chart (2256)

In 2256, just before the Battle of the Binary Stars, this star was displayed on a computer display monitoring the warp signatures of incoming Klingon starships aboard the USS Shenzhou. (TNG: "Allegiance"; DIS: "The Vulcan Hello")

When the Venari Ral laid Omega-47 mines around the core of Federation space in 3196, this system was within the blast radius of one of the mines. (SA: "300th Night", "Rubincon")

Stellar cartography

This system was visible from Earth in the constellation Ursa Major. It could be found in the asterism Big Dipper and was approximately 83 light years from Sol.

In the 2150s, this system's position was labeled on an United Earth star chart which was displayed in several crew and guest quarters aboard the Enterprise. (Star Trek: Enterprise, set decoration)

In 2259, the location of this system was labeled on a stellar cartography chart that was seen on the USS Enterprise's ready room viewscreen. This system's symbol had a blue color, indicating that it was affiliated with the United Federation of Planets. (SNW: "Strange New Worlds", "Spock Amok", "A Quality of Mercy")

On stardate 1292.4, the location of this system was labeled in a star chart used during a Section 31 Alpha Team briefing. (Star Trek: Section 31)

The system's location was labeled in a Federation star chart that was in Fleet Admiral Kirsten Clancy's office at Starfleet Headquarters in 2399 and on the bridge of the USS Titan-A in 2401. The Mizar system was in or near to Federation space. (PIC: "Maps and Legends", "The Next Generation", "Disengage")

In 2401, this system's position was labeled on a star chart used by Captain William T. Riker during his attempt at finding the last known location of the SS Eleos XII. (PIC: "The Next Generation")

In 3195, this system's position was labeled on a Federation star chart which was displayed in Starfleet Academy's Stellar Cartography laboratory. (SA: "Beta Test")

In 3196, during the Omega-47 crisis, the location of Mizar (Zeta Ursae Majoris) was depicted on star charts and readouts used across several locations on the USS Athena to locate, monitor, and respond to the Omega-47 mines laid by the Venari Ral. (SA: "300th Night", "Rubincon")

Appendices

Background information

The display showed part of the Big Dipper segment of Ursa Major.

Information on this system was derived from the episodes, from the reference works Star Trek: Star Charts and Stellar Cartography: The Starfleet Reference Library, and from real world sources. The reference works were used extensively in the creation of star charts seen in Star Trek: Discovery, Star Trek: Picard, Star Trek: Strange New Worlds, Star Trek: Prodigy, Star Trek: Lower Decks, and Star Trek: Starfleet Academy. The real-world information added to the article was current as of 2026.

The star chart seen in the series Star Trek: Enterprise made its first appearance in Crewman Daniels quarters in "Cold Front". It was also seen in several other episodes of the series, from 2151 to 2154. (For more information, see Federation star charts#United Earth Alpha/Beta star chart)

Apocrypha

In the Agents of Yesterday expansion pack of the Star Trek Online video game, Mizar IV was shown to be the site of a Federation colony, suggesting the possibility that the Mizarian system was located within Federation space and that Mizar itself could be a member on the Federation Council.

External links