Transparency · 3D Universe

What can be shown in true 3D

A three-dimensional universe is only as honest as its coordinates. This page states exactly which objects have measured positions and distances — and which do not — so every scene can be read for what it is.

The measured data

Measure	Count	What the scenes do with it
Stars with a measured distance	2,887 of 2,944	Placed in true 3D in the stellar-neighbourhood scene (parallax distance).
Stars without a measured distance	57	Excluded from every distance-true scene — never placed at a guessed position.
Stars with a measured direction	2,944	Right ascension and declination — enough for the celestial-sphere (direction-only) scenes.
Deep-sky objects with a direction	619 of 619	Direction and angular size only.
Deep-sky objects with a distance	0	The catalogue carries no line-of-sight distance for deep-sky objects, so none is placed in true 3D.
Planets with a real orbit	8	Real semi-major axes drive the to-scale Solar System scene.
Galactic structures (Milky Way)	11	Descriptive only — no numeric galactic geometry, so no galaxy-scale scene is fabricated.
Cosmic structures (Local Group +)	6	Descriptive scale labels only — no numeric inter-galactic distances.

How each scene is drawn

Constellations on the Celestial SphereInteractive
Direction only — the celestial sphere
Measured right ascension and declination placed on the unit celestial sphere (direction only — no distance is asserted by the position). Each star's measured distance is shown in the accompanying table.
The Local GroupDescriptive
Descriptive — no numeric geometry available
The catalogued galaxies and cosmic structures carry descriptive scale labels only — no numeric distance or coordinate — so no distance-true extragalactic scene is fabricated.
The Local Stellar Neighbourhood in 3DInteractive
Distance-true — real measured 3D positions
Measured right ascension and declination with a measured parallax distance (light-years) for each star, converted to real Cartesian positions. Stars without a measured distance are excluded — never placed.
The Milky WayDescriptive
Descriptive — no numeric geometry available
The catalogued galactic structures carry descriptive text only — no numeric coordinate or distance — so no galaxy-scale scene is fabricated. The only measured 3D geometry available at this scale is the local stellar neighbourhood, which is linked.
The Solar System in 3DInteractive
To scale — real relative distances
Real semi-major axes (astronomical units) from the solar-system catalogue; orbit sizes are to scale. Each planet is marked on its orbit at an illustrative angle — the along-orbit phase is schematic, not a computed ephemeris.

The rule

No position, distance, or coordinate is ever fabricated. An object with no measured distance is never placed in a distance-true scene; a structure with only a descriptive scale label is never given invented coordinates. See source quality.

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The measured data

Measure	Count	What the scenes do with it
Stars with a measured distance	2,887 of 2,944	Placed in true 3D in the stellar-neighbourhood scene (parallax distance).
Stars without a measured distance	57	Excluded from every distance-true scene — never placed at a guessed position.
Stars with a measured direction	2,944	Right ascension and declination — enough for the celestial-sphere (direction-only) scenes.
Deep-sky objects with a direction	619 of 619	Direction and angular size only.
Deep-sky objects with a distance	0	The catalogue carries no line-of-sight distance for deep-sky objects, so none is placed in true 3D.
Planets with a real orbit	8	Real semi-major axes drive the to-scale Solar System scene.
Galactic structures (Milky Way)	11	Descriptive only — no numeric galactic geometry, so no galaxy-scale scene is fabricated.
Cosmic structures (Local Group +)	6	Descriptive scale labels only — no numeric inter-galactic distances.

How each scene is drawn

Constellations on the Celestial SphereInteractive

Direction only — the celestial sphere

Measured right ascension and declination placed on the unit celestial sphere (direction only — no distance is asserted by the position). Each star's measured distance is shown in the accompanying table.

The Local GroupDescriptive

Descriptive — no numeric geometry available

The catalogued galaxies and cosmic structures carry descriptive scale labels only — no numeric distance or coordinate — so no distance-true extragalactic scene is fabricated.

The Local Stellar Neighbourhood in 3DInteractive

Distance-true — real measured 3D positions

Measured right ascension and declination with a measured parallax distance (light-years) for each star, converted to real Cartesian positions. Stars without a measured distance are excluded — never placed.

The Milky WayDescriptive

Descriptive — no numeric geometry available

The catalogued galactic structures carry descriptive text only — no numeric coordinate or distance — so no galaxy-scale scene is fabricated. The only measured 3D geometry available at this scale is the local stellar neighbourhood, which is linked.

The Solar System in 3DInteractive

To scale — real relative distances

Real semi-major axes (astronomical units) from the solar-system catalogue; orbit sizes are to scale. Each planet is marked on its orbit at an illustrative angle — the along-orbit phase is schematic, not a computed ephemeris.