← Sextant Lab

The 57 navigational stars and how to find them

The nautical almanac lists 57 bright stars chosen to be spread across the sky, plus Polaris. You never need all of them: at twilight, when both stars and horizon are visible, you pick three or four that are well separated in azimuth.

A few easy anchors in the northern sky:

• Polaris — its altitude is very nearly your latitude.
• Vega, Deneb, Altair — the Summer Triangle, high on summer evenings.
• Arcturus — "arc to Arcturus" along the handle of the Plough.
• Capella, Aldebaran, Betelgeuse, Rigel, Sirius — the winter sky around Orion.

A planisphere or a star-finder disc does the rest: set the local hour angle of Aries and read off which stars will be at a useful altitude at twilight.