An interactive astronomy engine — built for everyone, from your laptop to a full-dome planetarium.
Drive the celestial sphere through deep time. Watch the analemma trace itself, follow a gnomon's shadow across solstice arcs, or step outside the sky to see the whole framework at once.
Scenes
Each scene is a bookmarkable URL — drop straight into the right view.
Real stars, constellation lines and boundaries, asterisms, deep-sky objects, and the Milky Way — drawn on a clean horizon.
Open scene →The Sun's diurnal arc at solstices and equinox, with meridian, celestial equator, ecliptic, and today's path overlaid.
Open scene →A gnomon (śaṅku) on the ground, casting its real shadow as the Sun moves. Zodiac boundaries laid as arcs on the floor.
Open scene →The 27 nakshatras laid out along the sidereal ecliptic, with the live Sun–Moon tithi arc highlighted.
Open scene →Viewing modes
The same simulation reshapes itself for the screen in front of you.
Standard 60–90° perspective camera, anchored at the observer, looking outward. The everyday view on a laptop or monitor.
Step outside the celestial sphere and watch the whole grid framework rotate from afar. Useful for teaching the geometry itself.
A 5-camera cubemap cluster mapped to an equidistant fisheye shader — a true 1:1 DomeMaster ready for projection.
Stand inside the celestial sphere in stereoscopic WebXR — any browser-capable headset (Quest, Vive, Index) connects with one tap. No install.
Engine
The simulation primitives the scenes are composed from — all exposed in the operator console.
Dynamically resolves the precession of the equinoxes — shift cleanly between tropical and sidereal frames across deep time.
Adjustable wireframe sky with concentric altitude rings and azimuth meridians converging at the zenith. Customizable spacing.
From microsecond steps to cosmic timescales — same engine, same precision. Pause, scale, or lock the clock to a fixed time of day.
Sun, Moon, and the five classical planets — visible bodies tracked on the actual ephemeris, with per-body scale and labels.
A separate dark-mode control surface that runs on a phone or tablet over the local network — perfect for dome operators.
Run it anywhere
The same code powers the web app, the offline Windows build, and live full-dome projection. Pick the surface that fits.