Observing
How to read a sky map: azimuth and altitude
Turn a direction and an angle into a practical starting point for exploring your sky.
Two angles, one direction
Azimuth tells you which way to face: 0° is north, 90° east, 180° south and 270° west in Yorungez. Altitude measures the angle above the mathematical horizon. A target at 30° altitude is a third of the angular journey from the horizon to the zenith, not a third of its distance from Earth.
Check your context first
The same object has different local directions at different places and times. Confirm the observer position, local time zone and UTC instant before following a marker. Simulation explores a chosen time; return to live mode before comparing the map with the sky outside. Phone heading can need calibration against a known direction.
A marker is not a visibility guarantee
A positive geometric altitude does not account for trees, buildings, clouds or a bright sky. Yorungez's object centres are calculated without atmospheric refraction. Traditional rise/set predictions use a different convention. Treat the map as a direction guide and check the real horizon and observing conditions separately.
Sources & further reading
- Astronomy Engine: observer coordinates and horizon calculations ↗
- USNO: rise, set and twilight definitions ↗
These sources explain the scientific background. See the project page for Yorungez’s calculation and rendering limits. Science & project ↗