What you can see
The Plough is low on the left, in the north-west. Cassiopeia’s W-shaped pattern is high on the right, in the north-east. Polaris, the North Star, is near the middle of the chart, about 51.5 degrees above the northern horizon.
The lines join familiar star patterns. They are drawn on the illustration, not visible in the sky. The homepage uses a cropped version of the same chart.
Where the data comes from
The star positions are from the European Space Agency’s Hipparcos catalogue, available through CDS/VizieR. We calculated their positions in the London sky using Astropy, then projected them onto the chart.
This is a fixed illustration. It does not update with the time, weather or your location, and it is not a satellite coverage map. To find a position for a Starlink dish, use the Starlink app’s obstruction check.
- ESA Hipparcos catalogue via CDS/VizieR
- Astropy: calculating an observer’s view of the sky
- Royal Observatory: finding Polaris with the Plough
Calculation details
Observer: 51.5074° N, 0.1278° W. Reference time: 21:00 UTC on 24 September 2026, equivalent to 22:00 BST. The chart uses airless AltAz coordinates and a stereographic projection centred on north at an altitude of 45°. The calculated altitude of Polaris is 51.52°.
It uses approximate Earth-orientation values and ignores catalogue proper motion. These approximations are suitable for the illustration, which is not intended for precision pointing. Weather, light pollution and local obstructions are not simulated.