What is the Hipparcos catalogue?
Last updated 1 November 2026
The Hipparcos catalogue is one of the great star catalogues of modern astronomy, and from November 2026 every star we register comes from it. It is why your star has a HIP number on its certificate.
A satellite that measured the stars
Hipparcos was a European Space Agency satellite that spent 1989 to 1993 measuring the positions, distances and brightness of stars with a precision never achieved before. The results were published in 1997 as the Hipparcos catalogue: about 118,000 stars, each with its own HIP number.
Its name is a nod to Hipparchus, the Greek astronomer who made one of the first star catalogues more than two thousand years ago.
What your HIP number means
On your Certificate of Registry and co-ordinates sheet, your star's catalogue entry is shown as HIP followed by a number, for example HIP 113913. That is your star's identity in the catalogue astronomers use. Type it into planetarium software or a star-chart app and it will show you exactly the same star.
Your Database Number (ISD followed by seven digits) is different: it is your star's entry in the Intergalactic Star Database, and it is the number to use on our star finder.
Why we use it
- Every star is real and identifiable. Anyone can check a HIP number; it isn't a made-up co-ordinate.
- Precise positions. We can show your star exactly on a sky map and work out when it is up tonight.
- The right brightness. Most catalogue stars we name are just beyond the eye on its own and lovely in binoculars. Will I be able to see my star?
Registered before November 2026? Older stars in our original registry may be listed differently. See what you can do.