Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way.
The United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains the country's leading authority for astronomical and timing data for all purposes.
Stellar parallax is the apparent shift of position of any nearby star against the background of distant objects, and a basis for determining the distance of the object. Created by the different orbital positions of Earth, the extremely small observed shift is largest at time intervals of about six months, when Earth arrives at opposite sides of the Sun in its orbit, giving a baseline distance of about two astronomical units between observations. The parallax itself is considered to be half of this maximum, about equivalent to the observational shift that would occur due to the different positions of Earth and the Sun, a baseline of one astronomical unit (AU).
The Paris Observatory, a research institution of the Paris Sciences et Lettres University, is the foremost astronomical observatory of France, and one of the largest astronomical centers in the world. Its historic building is on the Left Bank of the Seine in central Paris, but most of the staff work on a satellite campus in Meudon, a suburb southwest of Paris.
Sir David Gill was a Scottish astronomer who is known for measuring astronomical distances, for astrophotography, and for geodesy. He spent much of his career in South Africa.
Leo Anton Karl de Ball was a German-Austrian astronomer. He is credited by the Minor Planet Center as "K. de Ball" for his (sole) asteroid discovery, but seems to be best known as Leo de Ball.
The Pulkovo Astronomical Observatory, officially named The Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, is the principal astronomical observatory of the Russian Academy of Sciences. It is located 19 km south of Saint Petersburg on Pulkovo Heights 75 metres (246 ft) above sea level. It is part of the UNESCO World Heritage Site Historic Centre of Saint Petersburg and Related Groups of Monuments. It was formerly known as the Imperial Observatory at Pulkowo.
A heliometer is an instrument originally designed for measuring the variation of the sun's diameter at different seasons of the year, but applied now to the modern form of the instrument which is capable of much wider use.
Hoher ListObservatorium is an Observatory located on the Hoher List mountain about 60 km south-west of the city of Bonn, close to the town of Daun in the Eifel region (Rhineland-Palatinate)
The Brera Observatory is an astronomical observatory in the Brera district of Milan, Italy. It was built in the historic Palazzo Brera in 1764 by the Jesuit astronomer Roger Boscovich. Following the suppression of the Jesuits by Clement XIV on 21 July 1773, the palace and the observatory passed to the then rulers of northern Italy, the Austrian Habsburg dynasty.
The Vienna Observatory is an astronomical observatory in Vienna, Austria. It is part of the University of Vienna. The first observatory was built in 1753–1754 on the roof of one of the university buildings.
The Yale University Observatory, also known as the Leitner Family Observatory and Planetarium, is an astronomical observatory owned and operated by Yale University, and maintained for student use. It is located in Farnham Memorial Gardens near the corner of Edwards and Prospect Streets, New Haven, Connecticut.
The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes mounted so as to allow pointing only in the meridian, the great circle through the north point of the horizon, the north celestial pole, the zenith, the south point of the horizon, the south celestial pole, and the nadir. Meridian telescopes rely on the rotation of the sky to bring objects into their field of view and are mounted on a fixed, horizontal, east–west axis.
The University of Illinois Astronomical Observatory, located at 901 S. Mathews Avenue in Urbana, Illinois, on the campus of the University of Illinois Urbana-Champaign, was built in 1896, and was designed by Charles A. Gunn. It has been listed on the National Register of Historic Places since November 6, 1986, and on December 20, 1989, was designated a National Historic Landmark.
Leibniz Institute for Astrophysics Potsdam (AIP) is a German research institute. It is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory Potsdam (AOP) founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP was founded in 1992, in a re-structuring following the German reunification.
Gotha Observatory was a German astronomical observatory located on Seeberg hill near Gotha, Thuringia, Germany. Initially the observatory was dedicated to astrometry, geodetic and meteorological observation and tracking the time.
Østervold Observatory is a former astronomical observatory in Copenhagen, Denmark owned and operated by the University of Copenhagen. It opened in 1861 as a replacement for the University's old observatory at Rundetårn.
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and success of this style in observational astronomy defines an era in modern telescopy in the 19th and early 20th century. Great refractors were large refracting telescopes using achromatic lenses. They were often the largest in the world, or largest in a region. Despite typical designs having smaller apertures than reflectors, great refractors offered a number of advantages and were popular for astronomy. It was also popular to exhibit large refractors at international exhibits, and examples of this include the Trophy Telescope at the 1851 Great Exhibition, and the Yerkes Great Refractor at the 1893 World's Fair in Chicago.
Göttingen Observatory is a German astronomical observatory located in Göttingen, Lower Saxony, Germany.
The Royal Observatory, Cape of Good Hope, is the oldest continuously existing scientific institution in South Africa. Founded by the British Board of Longitude in 1820, it now forms the headquarters building of the South African Astronomical Observatory.
