The Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics. The Smithsonian Astrophysical Observatory (SAO) operates ADS for the scientific community under a NASA cooperative agreement. At the request of NASA, ADS is expanding to bring similar services to scientists working in heliophysics, planetary science, and Earth science under the Science Explorer (SciX) label.

ADS maintains four bibliographic collections containing more than 28 million records covering publications in astronomy and astrophysics (including heliophysics and planetary science), physics, Earth science, and general science, including all arXiv e-prints. Abstracts and full-text of major astronomy and physics publications are indexed and searchable through the new ADS modern search form as well as a classic search form. A browsable paper form is also available. The multidiscplinary SciX interface looks similar to the ADS modern search form but provides enhanced functionality.

In addition to maintaining its bibliographic corpus, ADS tracks citations and usage of its records to provide advanced discovery and evaluation capabilities. Integrated in its collections, ADS provides access and pointers to a wealth of external resources, including electronic articles available from publishers’ websites, astronomical object information, data catalogs and data sets hosted by external archives. We currently have links to over 26 million records maintained by our collaborators. This depth of information has enabled a number of publications (refereed, non-refereed) in fields such as bibliometrics and information science.

Please note that ADS does not hold the copyright for the abstracts and articles, and their use is free for personal use only; open access abstracts and articles may have distinct terms. For more information, please read our page detailing the Terms and Conditions regulating the use of our resources.

Multiple societies and individuals have recognized the unsurpassed role that ADS plays in supporting the scientific community.

If you wish to acknowledge ADS in a publication, kindly use a phrase such as the following: “This research has made use of the Astrophysics Data System, funded by NASA under Cooperative Agreement 80NSSC25M7105.”