NOCTURNE is a fictional planetarium's almanac. Its hero is not a picture of the night sky — it is a working star chart: twelve real constellations plotted from right ascension and declination, wrapped on a band you can drag like the dome's own projector.
Planetariums sell precision wrapped in wonder. The page keeps that order: every number on it is real (star coordinates, magnitudes, meteor dates, ZHR rates), and the wonder is applied as craft — twinkle, brass, a Milky Way you'd only notice on the second visit.
Brass is the planetarium's own metal — the Zeiss projector, the door hardware, the railings. It marks everything human; starlight marks everything not.
Marcellus — display. Roman inscription capitals: the letterforms of observatories and museum lintels.
Crimson Pro Light — body. A bookish serif for almanac prose.
Overpass Mono — ephemeris voice: dates, rates, coordinates.
| Element | How it works |
|---|---|
| Star chart | Twelve constellations stored as [RA, Dec, magnitude] triplets with line-index pairs, projected onto a band 1.35× the viewport that wraps at 24 h. Dragging shifts the right-ascension offset with inertia; left idle, the sky turns at a slow sidereal drift. |
| Hover naming | Each frame computes constellation centroids; the nearest within 130 px lights its asterism in brass and floats its name beside it — the planetarium lecturer's laser pointer. |
| Star rendering | Size and alpha derive from real visual magnitude; background stars twinkle on individual sine phases; member stars carry a soft shadowBlur halo. |
| Meteors | Occasional gradient-tailed streaks spawn on a timer — frequent enough to catch, rare enough to feel lucky. |
| Moon month | Eight phases drawn on canvas: a dark disc, a half-disc lit hemisphere, and an ellipse terminator whose x-radius follows the illuminated fraction. |
| Accessibility | Reduced motion stops twinkle, drift, and meteors while the chart stays draggable. The canvas carries a descriptive aria-label; all almanac data is real HTML text. |
| You do | The page does |
|---|---|
| Drag the sky | The heavens turn with momentum, wrapping at 24 hours of right ascension |
| Rest near a constellation | Its lines light in brass and it introduces itself by name |
| Wait | Sidereal drift; sometimes, a meteor |
| Hover a meteor shower row | The row warms like a seat being saved |