What is a star map?

Star map: the short definition

A star map is a picture of the night sky as seen from one point on Earth at one moment. It is also called a star chart, a sky map or a night sky print.

As a gift, a custom star map carries a date that matters, the place where it happened and a few words: the night you met, your wedding day or the birth of a child.

How the sky of a date is calculated

The stars keep their positions relative to one another: the constellations we see today are the same ones people saw a hundred years ago. What changes is which part of the sky is above you, and that depends on three things.

• The place. Your latitude decides which stars can be seen. From London you never see the Southern Cross, and from Sydney you never see the North Star.
• The date. The Earth goes around the Sun once a year, so the sky on winter nights is not the sky on summer nights.
• The time. The Earth spins, and the whole sky seems to turn with it, about 15 degrees every hour.

With those three things and a star catalogue, which lists the position and brightness of every star, you can work out where each star was at that moment. It is the same calculation planetarium software does.

What a star map shows

• The stars you can see with the naked eye, drawn larger the brighter they are.
• The constellation lines, such as Orion, the Big Dipper or Cassiopeia.
• The Milky Way, the hazy band of our own galaxy.
• In some designs, the Moon in the phase it had that night.

Stelar Map Studio maps do not draw the planets. If you remember one very bright point, it may have been Venus or Jupiter, and it will not appear.

How to read a star map

Imagine lying on the ground and looking straight up. On a circular map, the centre is the zenith, the point right above you, and the edge is the horizon in every direction.

That is why east and west are swapped compared with a road map: with north at the top, east is on the left. It is not a mistake. You look down at a map of the ground, and up at a map of the sky.

Is a star map real or decorative?

Both. The positions are real: they come from an astronomical calculation, not from a generic drawing. On our maps, each star is placed with an error of under one degree, which on a 30 cm print is about one millimetre.

But it is a print, not a photograph or a scientific instrument. It does not show the clouds of that night or the city lights. And it shows the stars that were above that place even if it was daytime and the sun hid them.

Does the sky of a date repeat?

Partly. At the same time and from the same place, the stars come back to almost the same position every year. The Moon does not: each year it is in a different phase and a different part of the sky.

From one day to the next, at the same time, the sky shifts by about one degree. From one season to another it is completely different. And changing the city or the hour is enough to make it a different map.

What people give a star chart for

A star map marks a moment. The most common ones:

• An anniversary: the night you met, or your first kiss.
• A wedding: the sky of the day they said I do.
• A birth: the sky of the night the baby arrived.
• A memorial: a quiet way to keep someone present.
• Christmas, when you want a personal gift that arrives in time.

Digital or printed star map

You can buy a star map already printed, or as a file to print yourself. The file is yours the same day and lets you choose the paper, the size and the frame. The star map digital download page explains what you get and how to print it. And if you would rather make one yourself, here is how to make a star map, step by step.

By Stelar Map Studio · Updated October 6, 2026