Her Royal Madness Co.
The sky exactly as it stood, wherever you were.
The night you met. The night they were born. The night you buried someone, or left, or finally said it.
Enter the date, the time and the place, and it draws the real sky — every naked-eye star in its true position, all 89 constellations, the moon in the phase it actually was. Add a title and a line beneath, choose your ink, and download it at 2400 × 3200 — big enough to print at 8 × 10 or A4 and frame.
Unlimited maps, forever. Most star maps are made to order: one date, one file, £30. This is the machine that makes them. Make one for every person you love.
What you get: one HTML file. Double-click, opens in any browser, works offline, no account, doesn’t expire.
Six inks, optional constellation lines, star names, horizon grid and moon. Forty cities built in, or type any coordinates.
Star positions from the Hipparcos catalogue and constellation figures as defined by the International Astronomical Union — computed for your exact coordinates, not a stock picture of a sky that looks about right.
What it actually does
Enter a date, a time, a time zone and a place. It computes the local sidereal time, converts every star’s right ascension and declination into altitude and azimuth for those exact coordinates, and draws the sky as it stood — everything above the horizon, nothing below it.
All 5,044 naked-eye stars (to magnitude 6.0), sized by real brightness, with all 89 IAU constellation figures and 65 named stars labelled. The moon is drawn in its true phase for that night. Then a title, a line beneath, the date, the place and the coordinates — and a 2400 × 3200 PNG.
It is genuinely accurate, and I checked it four ways:
• Greenwich sidereal time at the J2000 epoch computes to 280.461° — the textbook value
• Polaris sits at the observer’s latitude, as it must
• Acrux is below the horizon from London and above it from Sydney
• The rendered sky puts Orion, the Plough and Cassiopeia where they belong for a January evening in Britain
That matters because the sky exactly as it was is the entire promise. It has to be true.
**works best on a computer, laptop, Mac.
