United States Naval Observatory
The United States Naval Observatory ( USNO ) is a research institute of the US Navy . It is located in the northwest part of Washington, DC
history
The institute was founded on December 6, 1830 as a naval observatory . The observatory achieved world fame under Simon Newcomb , when he put the astronomical fundamental system on a more precise basis through high-precision astrometric observations in the star and planetary system .
Around 1870 the observatory received one of the first of a worldwide series of giant telescopes with which the star locations and astronomical fundamental sizes were also significantly improved elsewhere. The USNO telescope had an opening of 26 inches (about 65 cm) and was the largest lens telescope in the world at the time with a focal length of over 10 m. With the opening of the new Vienna University Observatory , this rank was transferred to its 27-inch refractor for a few years.
The institute soon took on important international tasks, e. B. in the ephemeris and time service , in determining the longitude of the world in 1933 and in basic questions of navigation .
Today the USNO is one of the central offices of the International Service for Earth Rotation and Reference Systems (IERS).
Flagstaff Station
Since 1955, the USNO has also operated an observatory at an outstation near Flagstaff , Arizona ( ). Because of the better visibility conditions, a number of larger and more modern reflecting telescopes are operated here:
- 61-inch or 1.55-m Kaj Strand telescope
- 1.3 m (51 inch) reflector
- 1.0 m (40-inch) Ritchey-Chrétien telescope (the first?)
In addition, together with the Lowell Observatory in nearby Anderson Mesa, an optical interferometer that
- Navy Prototype Optical Interferometer (NPOI),
built. It consists of three arms, each 250 m long, in which the light from 6 siderostats with a diameter of 50 cm each can be coupled in via a vacuum tunnel and combined interferometrically to form an extremely high resolution image.
Kaj Strand Telescope
Navy Prototype Optical Interferometer at Anderson Mesa
Time signals
The observatory provides a highly accurate time service for military users. This time signal is also made available to civil users free of charge by calling +1 (202) 762-1401.
Residence of the Vice President
Since 1974 Number One Observatory Circle , a building on the site of the Naval Observatory, has been the official residence of the Vice President of the United States . However, Walter Mondale was the first resident to actually move in in 1977 . All Vice Presidents have used it since then.
Year 2000 problem
The year 2000 problem arose at the turn of the year into the new millennium. The USNO atomic clock was also affected. It was a bug in computer systems that resulted in the official website listing the year 19100.
See also
Web links
Individual evidence
- ↑ United States Naval Observatory: Our Command History , accessed December 5, 2010
Coordinates: 38 ° 55 ′ 17.3 ″ N , 77 ° 4 ′ 1 ″ W.