Virtual Catalog of National Libraries
Includes many Euopean and American libraries, plus some electronic full texts, provided by the Karlsruhe Institute of Technology.
Google Books
A great many digitized books, but only portions for those still under copyright. Advanced search allows you to limit your search to books with full view only. Example: Full books on astronomy.
Gallica
Digitized books from the National Library of France.
European Cultural Heritage Online
More than 300,000 high resolution images of historical sources, with collections in history of cosmology, history of mechanics, history of science, the scientific revolution, etc.
Astronomy Books in the Dresden Digital Library
Includes more than 200 items on 16th/17th-century astronomy, astrology, and books on astronomical instruments. Search on "astro*" to see a list.
Wilbour Hall
This site, a memorial to the former History of Mathematics Department at Brown University by Joseph G. Leichter, contains scans of many ancient astronomical texts.
NASA History Series Publications
Many books covering the history of the space program have been put online. NASA Technical Reports are also available. These contain over 200,000 full-text online documents and over 500,000 images and videos.
ARIBIB
The ARI Bibliographical Database for Astronomical References (ARIBIB) of the Astronomisches Rechen-Institut (Heidelberg) is the complete electronic version of the Astronomischer Jahresbericht, which listed the world’s astronomical publications from 1899–1968 and Astronomy and Astrophysics Abstracts, which covered the period 1969–2000.
The Smithsonian/NASA Astrophysics Data System (ADS)
Contains Astronomical Journal, Astronomy and Astrophysics, Astrophysical Journal, Astronomische Nachrichten, Icarus, Monthly Notices of the Royal Astronomical Society, The Observatory, Publications of the Astronomical Society of the Pacific, Quarterly Journal of the Royal Astronomical Society, and many, many more, including publications of observatories. Everything is free, thanks to NASA. NEW: Try streamlined search or search full text with ADS Labs.
Institute of Physics Journals
Many journals, including the Astronomical Journal since 1998, the Journal of Physics, and Chinese, European, and Russian journals. Mostly recent, but historic issues of some, such as Journal of Scientific Instruments and Transactions of the Optical Society. Costly.
Nature Archive
All articles back to 1869 may be purchased.
Physical Review Online Archive (PROLA)
Includes Physical Review Letters, Reviews of Modern Physics, etc. All articles since 1893 are available for a fee.
Physics Today archive
Full contents back to Volume 1 in 1948. Some articles are free.
SpringerLink
Includes more than 160 journals, 7 book series, and nearly 3000 books in physics and astronomy. Some are “Open Access” (free), but most are costly.
Wiley Interscience Journals in Physics and Astronomy
Includes Annalen der Physik, Annals of the New York Academy of Science, Astronomische Nachrichten, Astronomy & Geophysics, and a number of others. Note that some are costly here but free on ADS.
Antiquity
A quarterly review of World Archaeology. Archive may be browsed. Abstracts are free; articles may be purchased.
Archaeoastronomy: The Journal of Astronomy in Culture The Journal of the Center for Archaeoastronomy, published annually. Tables of contents available free on the site. Articles more than one year old may be purchased on the site.
The British Journal for the History of Science
Published for the British Society for the History of Science. All articles back to 1962 (and of its predecessor to 1955) are available for a fee.
Isis
Sponsored by the History of Science Society, it contains history of science, medicine, and technology, and their cultural influences. All articles are available—at a cost. Tables of contents and searching are free.
Journal for the History of Astronomy
The JHA, published quarterly. Tables of contents available free on the site. Most articles three years old and older are available free on ADS.
Journal of Astronomical History and Heritage The JAHH, published three times per year. All content back to 1998 is now available free on this site and also on ADS. Since 2012 the journal is published in electronic format only, but it is possible to download and print entire issues as well as individual papers from the JAHH site.
Revue d’histoire des sciences
Above site contains articles from 2011–2012 free and earlier ones for a hefty fee, but articles from 1947 through 2006 are available free through Persee.
AAS Obituary Index
Links to all obituaries published in the Bulletin of the American Astronomical Society. The obituaries are in ADS and are free.
The MacTutor History of Mathematics archive Extensive biographies and essays on historical topics. The definition of mathematicians is sufficiently elastic to include Edwin Hubble, and the topics include mathematical astronomy.
The Bruce Medalists
Photos, brief biographies, and extensive bibliographies of more than 100 astronomers honored since 1898 by the Astronomical Society of the Pacific.
The Galileo Project
Information on the life and work of Galileo Galilei and his contemporaries.
The Shapley-Curtis Debate in 1920 A number of articles and bibliographies related to the famous “debate” on the Scale of the Universe.
A Brief History of High Energy Astronomy
Provided by High Energy Astrophysics Science Archive Research Center (HEASARC), includes dates of missions, and even ancient astronomy-related events.
Early History of Radio Astronomy
by Woodruff T. Sullivan, III, author of several books on the subject. Includes links to more sources.
Starry Messenger
Some aspects of the early history of astronomy, drawing on the collection of instruments and books at the University of Cambridge, mostly from medieval times through Kepler.
Carnegie Institution Year Books
All of the year books of the Carnegie Institution for Science (formerly the Carnegie Institution of Washington) are available online. They include reports of the Mount Wilson Observatory.
American Physical Society Forum on the History of Physics
The Forum on the History of Physics, a member unit of the American Physical Society, was founded in 1980 to bring together physicists, historians, and other members of APS with an interest in the history of their subject and the impact of that history on culture, education, and physics research itself.
Antique Telescope Society
The Antique Telescope Society, Inc. is organized and operated exclusively for educational and/or scientific purposes. The purpose of the Society is to unite colleagues interested in antique telescopes, binoculars instruments, books, atlases and related items, and to promote the membership's interests in astronomical history and discovery, the history of optics, and the preservation and use of the antique instruments through stewardship and education.
British Society for the History of Science
The main organisation in the British Isles working to bring together people with an interest in the histories of science, technology and medicine and their changing relationship with society.
History of Science Society
The History of Science Society is the world's largest society dedicated to understanding science, technology, medicine, and their interactions with society in historical context.
Inter-Union Commission on the History of Astronomy
The Inter-Union Commission on the History of Astronomy is a joint Commission of the IAU and the International Union of the History and Philosophy of Science, Division of Science and Technology (IUHPS/DHST). The ICHA was founded in 2001 in order to create a Commission that involves and represents all historians of astronomy–including scholars who, being primarily historians rather than astronomers, are not members of the IAU. All members of C41 are, ipso facto, members of the ICHA.
SEAC, the European Society for Astronomy in Culture
A professional association of scientists working in the field of Astronomy in Culture or Anthropological Astronomy, including the interdisciplinary disciplines of Archaeoastronomy and Ethnoastronomy.
History of Astronomy
by Wolfgang R. Dick. Although not updated much recently, this remains the most complete website devoted to the history of astronomy.