The Real Sky, at Your Minute

What am I looking at?

The sky over one place at one minute, drawn the way an instrument reads it.

ProjectionZenith-centred stereographic. Horizon ring graduated every 5° of azimuth.

Picture yourself in an open field at that minute, lying on your back with your head to the north. The round view, the Dome, is everything you'd see from there, all the way down to the horizon. The centre is the point straight above you, the zenith. The ring is the horizon, marked off like a compass. The two dashed circles are the almucantars at 30° and 60° above the horizon: the lines of equal height that give the chart its name.

Four ways to frame it

The same sky comes in four views, and each one is drawn at the shape it prints, so the view you set in the studio is the view that arrives.

The Dome is the instrument face itself. Square sets the same face on a square sheet, with the ring drawn smaller so the corners reach 30° below the horizon, where the next stars to rise are waiting. Portrait is a tall 2:3 plate: the ring nearly meets the sides, and the top and bottom edges run down to 30° below the horizon. Panorama is a 3:2 window on the horizon, 150° across, from 10° below the horizon up to the zenith.

In the framed views the sky below the horizon is drawn dimmed under a veil of the ground, so you can see what was about to rise without mistaking it for what was up. A Panorama looks one way: toward the Sun while it sits near the horizon, and otherwise toward the meridian, due south from the northern hemisphere and due north from the southern.

Is it the real sky?

Yes. Every star, the Sun, the Moon and the planets sit where they were at your minute, computed rather than drawn by hand.

The positions are the fixed part. The colours are yours: the ground behind the stars, the ink the stars are printed in, or the sky's own colour at that minute. We keep those two things apart, so the print can be as bold as you like and the sky inside it still checks out against any atlas.

Stars9,096 entries of the Bright Star Catalogue, 5th ed., to magnitude 6.5, with proper motion carried to today.

The stars come from the Yale Bright Star Catalogue: every star down to magnitude 6.5, about the faintest a sharp eye finds under a dark country sky. At any minute about half of them are above the horizon. The Sun and the Moon come from Jean Meeus's Astronomical Algorithms, whose worked examples are this site's test suite, and the planets from orbital elements published by NASA's Jet Propulsion Laboratory.

PrecisionPlanets: well under 1′ for the inner planets; a few arcminutes at worst, for Saturn (Standish, Table 1, 1800–2050). The Moon is about 31′ wide.

How close is close enough? The inner planets land within an arcminute, a thirtieth of the Moon's width, and the outer ones within a few. On the largest print that's less than a millimetre, finer than the eye can find on paper at arm's length.

As Seen, and the solid grounds

As Seen paints the sky's own colour at your minute: the blue of day, the gold and rose of a sunset, the deep blue that follows, then night. Only the stars bright enough to show through that light are drawn, just as they'd have appeared. The colour is a model of a clear sky, tuned against photographs of twilight; it isn't a photograph of your evening, and it doesn't know about the clouds you had.

The solid grounds are one colour edge to edge, lifted a touch toward the zenith: Black, Red, White, Navy Blue and Sage Green, and eight night tones from Midnight to Forest.

What it leaves out

There are no galaxies, nebulae or star clusters drawn as objects, no satellites and no comets. Refraction near the horizon assumes a standard atmosphere, so on a cold night the lowest stars can sit a few arcminutes off. And the planets are only trusted between 1800 and 2050: outside those years they're drawn hollow, and the chart says so.

One more thing a print can't do: name a star. Nobody can sell that, and the International Astronomical Union doesn't recognise bought names. What you're hanging is the sky as it really stood, which we think is the better gift.

Why is east on the left?

Because a sky chart is read looking up, and a road map is read looking down.

Lay a map of your town on the table and east is on the right. Now lie on your back with your head to the north and look up: east is at your left hand. Planispheres and star atlases are printed that way for the same reason.

We keep it on every view, so a print you carry outside on a clear night lines up with the sky when you hold it overhead, its top toward the north. Fig. 1 above shows the compass points as they fall.

What does Gold mean?

Gold is a colour of printed ink: warm yellow stars and lines on the ground you choose, printed with the rest of the chart.

B−V, BSC5Rigel −0.03
Capella +0.80
Betelgeuse +1.85

There are three ways to colour the stars. True Colour gives each star its own colour from its B−V index, the catalogue's measure of how blue or red its light is: blue-white Rigel (β Ori), pale yellow Capella (α Aur), orange Betelgeuse (α Ori). Gold and Silver set every star and line in one ink, the same ink sets our sister shop, Painted Heavens, prints with. Each comes as a pair, one for dark grounds and a deeper one for light grounds, so the stars hold their contrast on White as well as on Midnight.

Because it's ink, Gold is a warm colour on the page, and it won't catch the light as you walk past. Better to know that now than on the day it arrives.

What happens after I order?

Prodigi or Printful, the two labs that make our sister shops' prints, prints your sky and ships it to you: whichever gets it there for less.

1. When you open checkout, your sky is drawn again at full print size from the same place, minute, view, ground and stars you set, so what you chose is what's printed.
2. You pay on Stripe's checkout page. We never see your card.
3. Your receipt arrives by email.
4. The lab the studio named prints it on the paper or canvas you picked, packs it and ships it, and you pay what it charges to send it, nothing more. We ship to the United States, Canada, the United Kingdom, Ireland, France, Germany, the Netherlands, Spain, Italy, Australia and New Zealand.
5. Prodigi publishes one to three days for the Fine Art Print, two to five for the Gallery Canvas and three to five for the Float-Framed Canvas (prodigi.com, checked 23 September 2026); Printful publishes two to five business days for everything it makes (printful.com, checked 6 October 2026). Shipping comes after that, and neither lab publishes a delivery date by country, so we don't either.

If it arrives damaged, or isn't the sky you set, write to support@painted.app within 30 days of delivery with a photo, and we'll remake it or refund you. The whole promise is on the shipping and returns page.

How it is computed

Meeus, 2nd ed.Ch. 7 time · 12 sidereal time · 13 horizontal coordinates · 16 refraction · 21 precession · 22 nutation · 25 Sun · 47 Moon · 48 phase

Every position is computed here, in your browser, at the moment you ask for it. Time runs through Julian Day and ΔT (Espenak and Meeus polynomials) to Terrestrial Time; Greenwich sidereal time, nutation, precession from J2000 and the obliquity follow Meeus, Astronomical Algorithms, chapters 12, 21 and 22. The Sun is chapter 25; the Moon is chapter 47, all 60 terms of longitude and 60 of latitude, with its phase from chapter 48; refraction is Sæmundsson's formula from chapter 16. The worked examples in those chapters are the test suite: the page ships only when its numbers match the book's.

The planets come from Standish's Keplerian elements, fitted for 1800 to 2050. That is arcminute work, not arcsecond work, and outside that window the page says so. Stars are the 9,096 entries of the Yale Bright Star Catalogue with a J2000 position: every star to magnitude 6.5, coloured by its B−V index. There are no deep-sky objects, no satellites and no comets.

What the sky shows

The faintest star drawn follows the Sun's altitude: magnitude 6.5 under a fully dark sky, falling through the twilights to nothing by day. In daylight you see the Sun, the Moon and perhaps Venus, which is what you would see. The "stars behind the daylight" switch on the chart overrides that for the curious.

The colour of the sky

The colour of the sky is a model, not a photograph: the Sun's height and bearing set a zenith, a horizon and a sunward glow, mixed in OKLCH so no step shows. After sunset the warm band stays on the Sun's side. Opposite it the Earth's shadow rises as a grey-blue band with the pink Belt of Venus along its top. By 18° below the horizon the sky is your tone's own ground, and from there only the stars change. The model is tuned by eye against twilight photographs; it is not a radiative-transfer calculation, and it does not know your weather, haze or light pollution.

The views, in figures

Panorama150° of azimuth × 100° of altitude, −10° to the zenith

Dome, Square and Portrait share one projection, zenith-centred stereographic, which keeps the shapes of the constellations true wherever they fall. Square shrinks the ring until its corners reach −30°. Portrait sets the ring so it meets the middle of each side at −8°, and its top and bottom edges reach −30°; it hangs tall, at 2:3. Panorama is a rectangular window in altitude and azimuth: at 150 by 100 degrees its horizontal and vertical scales are equal at the horizon, so the constellations there are not stretched. Toward the zenith a degree of azimuth spans less and less sky, so the top of a Panorama is widened, as every horizon panorama is.

Modes and tones on the chart

On the front page the chart has four modes. Sky is the default: the page itself follows the Sun, from pale Plate paper at noon through a rose dusk to the night tone you chose. The text turns from dark to light once, at the one point where both hold 4.5:1. Night keeps the dark ground at every hour, with true star colours; Plate is the printed star atlas, navy ink on pale paper; Red is for the eyepiece, and is a tool rather than a style. Night comes in eight tones, from Midnight to Forest; the stars keep their own colours in every one.

Drag, and the twilight shows

Drag the sky and the clock follows: the star under your finger stays under it. Hold Shift and drag up or down to step whole days.

Watch Tonight's Sunset sets the clock 25 minutes before the Sun goes down and plays one minute of sky every second, so the half hour or so of civil twilight passes in about half a minute. Watch the Dawn does the same before sunrise.

Privacy

Your place and time live in the address bar and, if you set a place, in this browser's local storage so the page opens where you left it. There are no cookies, no analytics, and no requests after the catalogue loads. Location is asked for only when you press the button. When you order, your name, email and shipping address go to the companies that take the payment and make the print; the privacy notice names each one.

Sources

1. D. Hoffleit and W. H. Warren Jr., The Bright Star Catalogue, 5th rev. ed. (1991), CDS V/50.
2. Jean Meeus, Astronomical Algorithms, 2nd ed., Willmann-Bell (1998), chapters 7, 12, 13, 16, 21, 22, 23, 25, 47 and 48.
3. E. M. Standish, Keplerian Elements for Approximate Positions of the Major Planets, JPL Solar System Dynamics (2006), Table 1.
4. F. Espenak and J. Meeus, Five Millennium Canon of Solar Eclipses: −1999 to +3000, NASA/TP-2006-214141 (2006), for the ΔT polynomials.
5. Constellation figures and the Milky Way outline: Olaf Frohn, d3-celestial, BSD-3.
6. Proper names follow the IAU Working Group on Star Names. Sky tones after the Painted Heavens backgrounds.

If you'd like to see it working first, the chart on the front page is the same instrument, live, for wherever you are. When you're ready, the studio is where you set your minute and choose the colours.