This standalone shell uses the same framework-neutral Celestia Atlas viewer as embedded applications. Stars, constellations, moving objects, reference layers, landscapes, and deep-sky objects therefore share one rendering implementation. It has no Aladin, Stellarium Web, external fonts, or online catalogue calls. At narrow fields, the optional DSS2 Color survey progressively adds real photographic sky imagery from a CDS-listed MAST mirror.

Data scope

The public build contains OpenNGC, all 86 Abell-1966 planetary nebulae, Abell/ACO galaxy clusters, the LDN, Barnard, LBN, Sharpless, vdB, and RCW groups, plus a HYG star layer through visual magnitude 6.5 with HD and SAO cross-identifiers, a Wolf-Rayet catalogue, and 63,291 GCVS named-variable entries available in offline search. Use Controls → Star catalogues to choose visible groups and raise the star magnitude limit to show faint targets. Stars without a measured magnitude appear as selectable markers when found in search. GCVS variable entries use J2000 coordinates and carry catalogue magnitude ranges and periods where available; they do not predict current brightness or add duplicate plotted stars. Catalogue coordinates use J2000/ICRS frames. Plotted stars use their available B-V colours, while galaxies and nebulae use type-specific symbols and scaled catalogue footprints. Faint objects appear progressively as you zoom in, while every bundled entry remains searchable offline. The Milky Way panorama and available local DSO images require no runtime network access. DSS tiles are requested on demand, may be cached after viewing, and fall back to the local panorama when a field is unavailable offline.

Catalogue attribution

OpenNGC and the HYG-derived star asset are separately distributed under CC BY-SA 4.0. The pinned SIMBAD A66, SAO and WR snapshots are distributed under ODbL 1.0. The Stellarium DSO supplement is distributed under GPL-2.0-or-later and retains Stellarium and original-catalogue credits. Richer tables imported locally from VizieR are not included in the public bundle; their source rights and redistribution terms require review. See docs/CATALOGUES.md and THIRD_PARTY_NOTICES.md for source-specific attribution, terms, and limitations.

Controls

Drag to pan, wheel or pinch to zoom, click an object for details, and use /, G, C, D, L, H, N, R, or F.

Offline installation

Serve this folder once on localhost and choose “Install app” in a compatible browser. The included service worker caches every required atlas file and can retain a bounded set of DSS tiles you have viewed. Unseen DSS fields still need a connection; the local atlas remains usable without them.