The free digital library of astronomy and astrophysics.
At a Glance
| Publisher | SAO/NASA Astrophysics Data System (Harvard–Smithsonian Center for Astrophysics) |
| Coverage | 28M+ records across astronomy, astrophysics, physics, and related fields, with deep citation linking and arXiv integration |
| Access | free; open API |
| Free alternative | it is free |
| Regional | global. |
Our Take
ADS is the beating heart of astronomy research — a free, comprehensive index with citation and reference linking, full-text search, and tight arXiv integration, so astronomers can move from a paper to its references, citations, and preprint in a couple of clicks. Its citation tooling rivals the commercial indexes within its field. It’s discipline-bound to the physical sciences, which is exactly the point. Use it as the primary index and citation tool for astronomy and astrophysics; its API is excellent for field-level bibliometrics.
Power Tips
- Use ADS’s citation and reference links (and arXiv integration) to traverse a topic the way you would in Web of Science — free, and deeper within astronomy
- pull field bibliometrics through the open API without a subscription.
Alternatives & Complements
arXiv (astro-ph) · Scopus · Web of Science · OpenAlex.
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