# Stellarium/stellarium

Stellarium is a free GPL software which renders realistic skies in real time with OpenGL. It is available for Linux/Unix, Windows, macOS and Haiku. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope.

Repository: https://github.com/Stellarium/stellarium
Canonical: https://ross.abutalabs.com/products/stellarium
Homepage: https://stellarium.org
Language: C++
License: GPL-2.0
License Family: copyleft
Topics: c, c-plus-plus, astronomy, science, stars, sky, universe, planetarium, stellarium, qt5, qt6
Last push: 2026-08-26T16:52:42+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 78, longevity 100
- inputs: {"age_days": 4525, "days_push": 7, "days_rel": 70, "gap_med": 90, "n_releases_24m": 8}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 9897, forks 1042 (observed 2026-08-28T04:10:38.713349+00:00)

## What it is
Stellarium is a free open-source planetarium application that renders a realistic 3D sky in real time using OpenGL, showing what is visible to the naked eye, binoculars, or a small telescope. It is built with C++ and Qt and runs on Linux/Unix, Windows, macOS, and Haiku.

## Use cases
- identify stars and constellations in the night sky
- plan telescope observing sessions
- simulate the sky at any date, time, and location
- learn astronomy with a realistic 3D planetarium
- view planets, nebulae, and the Milky Way in 3D
- teach astronomy in classrooms
- track shooting stars and meteor showers

## When to choose
- you want a free, realistic desktop planetarium for stargazing or astronomy education
- you need cross-platform sky simulation with extensive star and deep-sky catalogues
- you want scriptable, plugin-extensible astronomy software with a mature codebase

## When to avoid
- you need a lightweight web-only tool without installing a desktop application
- you require professional telescope control or research-grade astrometry beyond a planetarium's scope
- you need a mobile-first stargazing app

## Facets
- artifact type: application
- maturity: stable
- function: graphics, simulation, gui, data-visualization
- domain: astronomy, education, simulation, cross-platform
- platform: windows, cross-platform, cpp
- tags: planetarium, opengl, qt, stargazing, telescope, sky-rendering, open-source, science, linux, macos, desktop

## Member repositories
- Stellarium/stellarium (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:38.713349+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:20:21.012889+00:00, confidence not recorded.
  - readme: https://github.com/Stellarium/stellarium (fetched 2026-08-28T04:10:38.713349+00:00, sha 021921815cd0)
  - homepage: https://stellarium.org (fetched 2026-08-29T08:20:07.718826+00:00, sha 516cb8a7f4ea)
  - site_page: https://stellarium.org/en/docs.html (fetched 2026-08-29T08:20:07.728282+00:00, sha ba400a717fc4)
- Data as of 2026-08-30T08:39:29.467469+00:00.