Apphemeride Precise Astronomy

Observe or predict sky events, create watchlists, find photo opportunities, and get alerts—for the Sun, Moon, planets, and over 9,000 stars.

Track the sky from any location

Apphemeride helps you follow current sky events, spot future events early, and explore past, present, and future phenomena. Run location-based calculations for your current location or any place on Earth.

Scan for special configurations of planets, moons, and stars, as well as meteor showers. Find out when an event can be observed or photographed, display it on the sky map, or jump straight to the objects involved.

The expanded sky map now offers multiple orientation modes, constellations, more than 9,000 stars, and a visibility filter. Create personal watchlists for your favorite celestial bodies and the astronomical values that matter to you. Set alerts for when a selected value reaches, exceeds, or drops below your threshold.

Explore detailed data for the Sun, Moon, planets, Pluto, Chiron, and more than 9,000 stars. Depending on the celestial body, examine rise, meridian transit, and set times, azimuth and altitude, coordinates, twilight, illumination, phase, brightness, angular diameter, distances, and rates of change. View planet positions in the sky or solar system and analyze solar and lunar eclipses with maps and visual simulations.

Use the Horizon Tracker to study how the Sun, Moon, or planets move across your local horizon. Compare azimuth and altitude over a day, month, or year and plan observations for a particular viewing direction.

Where the sky is darkest, there is often no signal. Apphemeride still works: all astronomical calculations and observation tools are available offline—at remote observing sites, in the desert, or out at sea. Only street and address search requires an internet connection.

Customize values, units, formats, and precision to match the way you work. Apphemeride is not a simple star finder, but a comprehensive tool for astronomy enthusiasts, astrophotographers, travelers, and anyone who wants to understand movements in the sky precisely.

New users can try all astronomy features free for three days. Afterwards, a one-time in-app purchase unlocks them permanently. Anyone who bought Apphemeride before the transition automatically keeps permanent access.