When you receive your NamedLight registration, one of the first things you'll notice is the sky chart: a circular view of the night sky with your star at the center. It's one of the details that makes a NamedLight registration feel grounded rather than generic. Here's exactly how that chart is made.
It's Rendered From Real Star Catalog Data
Your sky chart is not a stock photo and not a decorative illustration. It's rendered by NamedLight from real astronomical catalog data, so every star you see on it is a real star, drawn at its catalogued position in the sky. It's a chart, not a photograph, and we think that's worth being clear about.
Two catalogs supply the data:
- UCAC4, the Fourth U.S. Naval Observatory CCD Astrograph Catalog. Produced by the U.S. Naval Observatory, it records the precise positions of more than 100 million stars across the entire sky, including stars far too faint to see with the naked eye.
- The HYG Database, which combines the Hipparcos, Yale Bright Star, and Gliese catalogs. It provides the brighter stars, including your own star's coordinates, brightness, and distance.
How the Chart Is Centered on Your Star
When your registration is processed, we take your star's right ascension and declination from the HYG Database and place your star at the exact center of the chart. Every star within the surrounding field, a patch of sky about two degrees across, roughly four times the width of the full Moon, is then plotted from the catalogs at its real position, with north at the top.
Each star is drawn according to its measured brightness, so brighter stars appear larger and more prominent, and fainter ones appear as smaller points. Star colors are based on catalog color measurements where they're available, which is why some stars on your chart look warmer or bluer than others.
The reticle, the small circle at the center of the chart, marks your star's exact position.
Why Some Sky Charts Look Richer Than Others
Not every patch of sky looks the same, and your sky chart reflects that honestly. A star in Sagittarius or Cygnus, near the dense band of the Milky Way, produces a chart crowded with thousands of stars. A star in a quieter region of sky, away from the galactic plane, shows a sparser field with fewer stars around it.
Neither is better than the other. A sparse field has its own quiet beauty: deep space, a few steady points of light, and your star at the center. A rich field shows your star embedded in the dense fabric of the galaxy. Both are real, because both come straight from the catalog.
Why We Render Charts Instead of Using Photographs
Rendering from catalog data gives every registration a clean, consistent chart that is accurate to the star's real coordinates, with no camera artifacts, plate defects, or gaps in coverage. Because the catalogs cover the whole sky, every star in our registry gets a chart built the same way.
It also means everything on the chart can be checked. Your registry page lists your star's HYG catalog ID and coordinates, and you can look up the same stars yourself in any planetarium app or star catalog.
Star Data Credits
UCAC4 is produced by the U.S. Naval Observatory and is a U.S. Government work in the public domain. The HYG Database by David Nash is licensed under CC BY-SA 4.0.
If you're ever unhappy with your sky chart for any reason, contact us within 30 days and we'll assign a new star and send you a new certificate at no charge.