Mathematical assumptions
Sunrise is anchored to -0.833 degrees solar altitude, combining standard atmospheric refraction and the solar semi-diameter used for upper-limb sunrise estimates.
Astronomy
Pre-Dawn Sunrise Star Map
Visualise the celestial bodies visible exactly one hour before the sun crests the horizon. The stereographic projection aligns strictly with the true astronomical sunrise azimuth for your selected observation coordinate, correcting for disc and refraction.
Parameters
Sunrise star maps rely on date, location and true horizon geometry.
Geolocation
Latitude51.5072°N
Longitude0.1276°W
Syncing celestial catalog...
Methodology & Accuracy
Calculation method and limits
The page combines a standard sunrise altitude correction, Julian-date solar position arithmetic and local sidereal time to draw a practical pre-dawn sky view.
Sky projection
The map evaluates local sidereal time, projects visible stars above the horizon, and centres the view on the calculated sunrise azimuth.
Horizon limitations
Results assume a level mathematical horizon. Hills, buildings, elevation, weather and magnetic declination can change field observations.