Cambridge Optical Aperture Synthesis Telescope - A multi-element optical interferometer with baselines of up to 100 meters, designed to observe stars with angular resolution as high as one thousandth of one arcsecond.
Carnegie Observatories - Information for observers, calendar, publications and libraries, seminars and conferences, fellowship program, and links.
InfraRed Telescope Facility - General information, observing information, instrumentation, facility systems, photo gallery, news, and links.
Keck Interferometer - A ground-based component of NASA's Origins Program that addresses fundamental questions about the formation of galaxies, stars, and planetary systems, the prevalence of planetary systems around other stars, and the formation of life on Earth.
Kitt Peak National Observatory - General information, image gallery, facility schedule, documentation, observation information, documentation, and electronic forms and tools.
Lowell Observatory - Research, education and outreach, mission, star tales, and links.
McDonald Observatory - Facility information, equipment and instrumentation, observer information, and research.
Mount Laguna Observatory - Facilities, equipment and instrumentation information, virtual tour, site map, CCD camera laboratory and production, and resources.
National Optical Astronomy Observatory - Information, news, resources, outreach programs, gallery, observing information, software, and newsletter and reports.
Sloan Digital Sky Survey - A dedicated 2.5 meter telescope which uses sensitive electronic light detectors to systematically map a quarter of the sky, building a catalog of celestial objects, galaxies, and quasars. Data links, questions and answers, image gallery, project tour, news, archive, publications, and links.
Spitzer Space Telescope - General information, articles, downloads, equipment information, news, and links.
Steward Observatory - Equipment information, projects, calendar, talks, news, and links.
