Personalized Constellation Map Print
The constellations over your moment, drawn as classic stick figures — not clip-art, but the actual figures that were above the horizon, computed from their star coordinates.
Draw your constellations
Free, in your browser — no account, nothing uploaded. Both downloads are the complete chart: a vector SVG and a 300 dpi PNG, with nothing held back and nothing to buy.
The generator carries the 89 modern IAU constellations (the familiar “Western” figures, as used by Stellarium), each defined by real star coordinates. For your date, time and place it projects every figure into the sky disc and clips it at the horizon — so Orion appears exactly as much of Orion as had risen.
Depending on your latitude and hour, roughly 25–45 constellations are at least partly visible at once. The brightest stars get name labels — Sirius, Vega, Capella, whichever were up — and every dot is scaled to the star's true brightness, so the map reads like the sky rather than a scatter plot.
How the map is computed
You give it three things: a date, a time, and a place. For the place, type a town or city name and pick it from the list — 29,919 towns and cities of 18,000 people or more, from GeoNames — or enter an exact latitude and longitude instead. Accents are optional (“malmo” finds Malmö), but type the name on its own: “Roskilde Denmark” finds nothing, and a typo finds nothing rather than the wrong sky.
Your date, time and place are converted to a Julian Date and then to local sidereal time — the astronomer’s clock for “which way is the sky facing.” Each of the 1,630 stars in the Yale Bright Star Catalogue (every star brighter than magnitude 5.0, i.e. every star a good naked eye can see) is transformed to its altitude and azimuth at that exact moment, and every one of those stars above the horizon is projected onto the circular chart: zenith at the centre, horizon at the rim, north at the top — and east on the left, because a star map is read looking up, which mirrors east and west compared to a ground map.
The 89 constellation figures are drawn with the same math and clipped at the horizon. Star dots are scaled by real brightness (magnitude) and tinted by star colour. The Moon is drawn at its real altitude, azimuth and phase for your moment, and left off entirely when it was below your horizon. It does not show the planets, comets or satellites — those wander against the fixed stars and need ephemerides, which this version does not compute. Everything runs in your browser — nothing is uploaded, there is no account, and the page works offline once loaded.
Common questions
How many constellations will be on my map?
Typically 25–45 at least partly above the horizon, depending on latitude and time. Observers near the equator see the most; polar observers see fewer figures but keep them all night.
Will my zodiac constellation appear on my birthday map?
Usually not, and it's worth knowing why: your sun sign is the constellation nearest the sun on your birthday, so it's up in daylight and set at night. Look for it on a map dated about six months from your birthday instead.
Are the constellation names printed on the chart?
v1 labels the brightest stars, not the constellation figures — name labels for the figures are on the backlog. The figures themselves are all drawn.