Stellarium 26.1: planetarium updates

# Stellarium 26.1: Key Updates in the Open-Source Planetarium

Stellarium 26.1 was released on April 5, 2026 — the first update of 2026 following the 25.1 release in March 2025. The version focuses on bug fixes, core optimization, and expanded support for sky cultures. The GPLv2-licensed project is available for Linux, Windows, macOS, and a web version via GitHub.

Stellarium renders a database of 600 thousand stars and 80 thousand objects, with the option to expand to 220 million stars and a million deep-sky objects. It supports 3D visualization, dome projection, and telescope integration via plugins.

Improvements in Core and Modules

In version 26.1, the core has been refined: algorithms for calculating positions of Solar System bodies have been optimized for better performance. Photometry has been improved, data on minor bodies, planetary features, comets, and satellites updated. The graphical interface is more responsive, and localization has been expanded.

Core and AstroCalc modules received numerous fixes. Support for zodiacal and lunar coordinate systems has been added, simplifying astronomical calculations. The Time Navigator plugin has been enhanced with a 'Planetary Events' feature and a new time step — the Metonic cycle (19 years).

New Sky Cultures

Expanded Sky Cultures option:

• Added Chinese (Xianglin star map) and Manchu cultures.
• Support for non-standard regions.
• Two new sky cultures.

Updated existing ones:

• Babylonian (MUL.APIN).
• Scandinavian (Edda).

Moon rendering improved: scaling depends on the field of view. Moon albedo texture updated, planetary nomenclature brought up to date.

Plugins and Telescopes

TelescopeControl plugin fixed for Qt6, especially for ASCOM telescopes. Developers note: "Check if this resolves your control issues. Looking for C++ developers to refine it — rewards possible".

Solar System Editor integrated a link to the list of bright minor planets in opposition from MPC for 2026. Scripts now support selecting planetary objects. Duplicates removed: page_surveys, culture mockups, discrete GPU auto-selection code; minimumSize parameter from culturesListWidget.

Catalogs updated:

• DSO up to 3.23.
• Exoplanets (by default).
• Comets and minor planets.
• Comet/asteroid discovery conditions.
• Satellite photometry.

Windows/arm64 support improved. Minor planet detection conditions fixed.

Key Highlights

• Performance: Optimized Solar System position calculations, fixes in Core/AstroCalc.
• Cultures: +2 new (Chinese, Manchu), updates to Babylonian/Scandinavian.
• Plugins: Time Navigator with Metonic cycle and planetary events; TelescopeControl for Qt6/ASCOM.
• Data: Updated DSO, exoplanet, comet catalogs; Moon texture.
• Platforms: Improvements for Windows/arm64, scripts with planetary objects.

The total number of changes exceeds 30 items, with emphasis on stability and data expansion. For mid/senior developers: source code on GitHub is open for contributions, focus on Qt6 and astronomical algorithms.

— Editorial Team