One of the most recognizable constellations in the sky.
M31
Andromeda GalaxyGalaxy
Magnitude3.4
Angular Size190' × 60'
Distance2.5 million light-years
CoordinatesRA 0h 42m, Dec +41°
The nearest major galaxy to the Milky Way.
Once Around the Night Sky
About
An interactive visualizer for
Paul Fellows'
excellent "Once Around" series of astronomy YouTube videos.
Explore the night sky and discover the celestial objects featured in the series.
Data Sources
Stars: Hipparcos Catalogue (~118,000 stars) with fallback to Yale Bright Star Catalog
Planets: VSOP87 planetary theory for high-precision positions
Moon: Simplified lunar ephemeris based on Meeus's Astronomical Algorithms
Constellations: IAU constellation boundaries with stick figures