The National Solar Observatory (NSO) is a United States federally funded research and development center to advance the knowledge of the physics of the Sun.
NSO is headquartered in Boulder and operates facilities at a number of locations – at the 4-meter Daniel K. Inouye Solar Telescope in the Haleakala Observatory on the island of Maui, at Sacramento Peak near Sunspot in New Mexico, and six sites around the world for the Global Oscillations Network Group one of which is shared with the Synoptic Optical Long-term Investigations of the Sun.
It operates facilities, develops advanced instrumentation both in-house and through partnerships, conducts solar research, and carries out educational and public outreach.
[1] These instruments were followed by the Evans Solar Facility, or Big Dome, which housed a 16-inch (41 cm) coronograph and spectrograph.
The site's name was chosen by the late James C. Sadler, (1920–2005), an internationally noted meteorologist and professor at The University of Hawaii, formerly with the United States Air Force on assignment during the early inception of the observatory.