List of stars for navigation

When navigating in the Northern Hemisphere, a simple and quick technique can be used with Polaris to determine the observers latitude or, for larger maritime vessels can be used to calculate any gyrocompass error that may exist.

The other fifty-seven selected stars have daily positions given in nautical almanacs, aiding the navigator in efficiently performing observations on them.

Although Polaris can quickly and simply give a solution for latitude in the northern hemisphere, it can not participate in giving a position fix including longitude - it is for this reason it is excluded from the list of 57 primary navigational stars, each of which can be used to produce (in conjunction with each other, known time in relation to the prime meridian and a set of sight reduction tables) an actual latitudinal and longitudinal positional fix.

For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree.

In practical use for sight reductions whilst at sea, tables can further assist a navigator by giving approximate altitudes (angles above the horizon) and azimuths (degrees as read from the compass) from an assumed or estimated position, usually helping to quickly determine the location and then quickly identify a particular navigational star that may be useful for a sight reduction.

[6] Positions on the celestial sphere are often expressed using two coordinates: declination and sidereal hour angle, which are similar to latitude and longitude on the surface of the Earth.

References like the Nautical Almanac and The American Practical Navigator provide four star charts, covering different portions of the celestial sphere.

The additional 115 tabulated stars that can also be used for navigation are shown in red and labelled with a Greek letter to indicate their Bayer designation.

Some additional stars not suitable for navigation are also included on the charts to indicate constellations, they are presented as unlabelled small red dots.

The equatorial region of the celestial sphere's eastern hemisphere includes 17 navigational stars from Alpheratz in the constellation Andromeda to Denebola in Leo.

It also includes stars from the constellations Cetus, Aries, Taurus, Orion, Canis Major and Minor, Gemini, and Hydra.

The equatorial region of the celestial sphere's western hemisphere includes 13 navigational stars from Gienah in the constellation Corvus to Markab in Pegasus.

It also includes stars from the constellations Virgo, Bootes, Libra, Corona Borealis, Scorpio, Ophiuchus, Sagittarius, and Aquila.