(covers information from several alternate timelines)
In 2293, Alpha Carinae's location in the Milky Way Galaxy was labeled in the star chart "The Explored Galaxy", which was on display in Captain James T. Kirk's quarters aboard the USS Enterprise-A. (Star Trek VI: The Undiscovered Country okudagram)
In 2366, in an alternate timeline, during the Federation-Klingon War, the location of Alpha Carinae was labeled on a tactical situation monitor in the ready room aboard the USS Enterprise-D. (TNG: "Yesterday's Enterprise" okudagram)
|Alpha Carinae system|
|Alpha Carinae I • Alpha Carinae II • Alpha Carinae V|
Alpha Carinae and Canopus are depicted as being two separate stars on a star chart first seen in Star Trek VI: The Undiscovered Country and subsequently reused in a number of Star Trek episodes. In reality, these are two different names for the same star.  This contradiction is also noted in the Star Trek Encyclopedia (4th ed., vol. 1, p. 115) and, according to Star Trek: Star Charts (p. 65) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), Canopus (Alpha Carinae) is a star in the Beta Quadrant. The primary was a F-class star.
For Star Trek: First Contact, Alex Jaeger created a ship size comparison chart for Industrial Light & Magic. On this chart, one of the names considered for the Norway-class starship was the USS Canopus.