ADS maintains three bibliographic databases containing more than 8.5 million records: Astronomy and Astrophysics, Physics, and arXiv e-prints.

arXiv.org is a highly-automated electronic archive and distribution server for research articles. Covered areas include physics, mathematics, computer science, nonlinear sciences, quantitative biology and statistics. Select "Physics" from the subject box to and then astro-ph from the Physics drop-down menu to search astrophysics materials.

Definitions, background information, and more for getting started.

Detailed information and analysis in print and online ebook formats.

Charts, atlases, maps, manuals, and more for the night sky and beyond.

Databases, journals, and magazines for locating the latest research, news, and more.

How we define the process and how to identify peer-reviewed sources.

Find cutting edge research ahead of journal publication.

Find extensive, in-depth information from dissertations and theses.

Examples, guides, and citation management help for a variety of styles.