Tonight's Sky

The fourteen stars shown on this chart are the principal navigation stars used in celestial navigation. Selected for brightness and distribution across the sky, they are the stars a navigator learns to identify and observe with a sextant.

The chart shows which of these stars are above the horizon at your chosen time and position. Azimuth runs along the horizontal axis — compass bearing from North through East. Altitude on the vertical — degrees above the horizon. Stars are marked with + in gold, planets with × in white.

Planning evening sights

For celestial navigation at sea, the ideal observation window is nautical twilight — roughly 30 to 50 minutes after sunset, when the horizon is still visible but the brightest stars have appeared. Use the “Set to twilight” button to jump to this time for your date and location.

Knowing which stars and planets will be visible helps you plan your evening sights. Identify three or four well-separated bodies in advance, note their approximate bearings, and you can work quickly on deck when the moment comes.

The navigation stars

The chart includes Sirius, Canopus, Arcturus, Rigel, Procyon, Deneb, Vega, Altair, Spica, Capella, Pollux, Aldebaran, Polaris, and Betelgeuse. These fourteen cover the full range of right ascension and declination, ensuring that several are always visible from any latitude at any time of year.

Four planets are also tracked: Venus, Mars, Jupiter, and Saturn. When above the horizon, planets are excellent sextant targets — bright, unambiguous, and listed in every nautical almanac.

From chart to sextant

Once you have identified your targets, use the Intercept tool to reduce your sextant observations and plot lines of position. The sky chart tells you what to shoot; Intercept tells you where you are.