Stellarium

The software renders a three‑dimensional, real‑time view of the night sky that matches what an observer would see with the naked eye, binoculars or a telescope. It includes a default catalogue of more than 600 000 stars and 80 000 deep‑sky objects, with optional extensions that add hundreds of millions of stars and millions of nebulae. Users can display constellations, their boundaries, cultural star maps, and the Milky Way, and can toggle atmospheric effects such as sunrise, sunset and realistic sky colour.

It is aimed at amateur astronomers, educators and anyone interested in exploring celestial objects without specialised equipment. The interface offers zoom, time‑control, and scripting capabilities, allowing users to create presentations or custom visualisations. Multilingual support covers dozens of languages, and the program runs on macOS, Windows and Linux platforms using Qt5/Qt6.

The application is free and open source, with a stable release status. It provides extensive data from all‑sky surveys, detailed planetary and satellite models, and a range of visual options for deep‑sky objects and nebulae, making it a practical tool for both casual observation and instructional use.