The North Star was a passenger train operated by Amtrak along the "Hiawatha Corridor" during the late 1970s and early- to mid-1980s. It originally operated as a Chicago, Illinois–Duluth, Minnesota train via Saint Paul, Minnesota, but was soon converted to a Saint Paul–Duluth local. The service relied in part on funding from the state of Minnesota.

The North Star was introduced in the spring of 1978, when Amtrak moved Twin Cities operations from the Great Northern Depot in Minneapolis to Midway station in Saint Paul and combined the previous Chicago–Minneapolis Twin Cities Hiawatha and the Minneapolis–Duluth Arrowhead services into one train. Where the Arrowhead was a 148-mile (238 km) local, the North Star was a 573-mile (922 km) sleeper originating in Chicago, Illinois, departing there at 10:30 PM in the initial schedule. It took 8 hours 45 minutes to reach Saint Paul, where there was a 35-minute layover. It then took another 3:45 to reach Duluth for an overall schedule of just over 13 hours from Chicago.

A pole star is a visible star, an especially prominent one, that is approximately aligned with the Earth's axis of rotation; that is, a star whose apparent position is close to one of the celestial poles, and which lies approximately directly overhead when viewed from the Earth's North Pole or South Pole. A similar concept also applies to other planets. In practice, the term Pole Star usually refers to Polaris, which is the current northern pole star, also known as the North Star.

The south celestial pole currently lacks a bright star like Polaris to mark its position. At present, the naked-eye star nearest to this imaginary point is the faint Sigma Octantis, which is sometimes known as the South Star.

While other stars' apparent positions in the sky change throughout the night, as they appear to rotate around the celestial poles, pole stars' apparent positions remain virtually fixed. This makes them especially useful in celestial navigation: they are a dependable indicator of the direction toward the respective geographic pole although not exact; they are virtully fixed, and their angle of elevation can also be used to determine latitude.