Dictionaries
- Absolute Astronomy Encyclopedia of Science Encyclopedic articles on the objects in the sky plus terms from other sciences
- Astronomy Thesaurus Synonyms of words used in astronomy.
- Eric Weisstein's Dictionary of Astronomy
- Nomenclature of Celestial Objects Dictionary with full references on the designations of astronomical objects and their acronyms.
- On-Line Glossary of Solar-Terrestrial Terms
