# Washington Double Star Catalog

Also called: WDS, STF, Struve.

The US Naval Observatory's master catalog of double stars, with more than 150,000 pairs.

The WDS collects measurements of double stars going back two centuries. Its discoverer codes appear in names: STF is Friedrich Struve, whose 1827 catalog listed 3,000 pairs (Struve 747, say); H is William Herschel.

**In AstroPilot:** AstroPilot's double-star separations and position angles come from the WDS.

**Examples:** [struve-747](https://astropilot.space/object/struve-747.md), [albireo](https://astropilot.space/object/albireo.md)

**Related:** [Double star](https://astropilot.space/glossary/double-star.md), [Star names & designations](https://astropilot.space/glossary/bayer-designation.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/wds