The ''Astronomische Gesellschaft Katalog'' (AGK) is an

astrometric 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. History ...

star catalogue A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the year ...

of the Northern hemisphere. It was published in 3 versions from 1890 until 1975, named AGK1, AGK2 and AGK3.

History

Compilation for the first version, Astronomische Gesellschaft Katalog 1 AGK1, was started in 1867, directed by

Friedrich Argelander Friedrich Wilhelm August Argelander (22 March 1799 – 17 February 1875) was a German astronomer. He is known for his determinations of stellar brightnesses, positions, and distances. Life and work Argelander was born in Memel in the Kingd ...

and published between 1890 (three sections from the observatories at Oslo, Helsinki, and

Neuchâtel Observatory The Neuchâtel Observatory () is an astronomical observatory funded by the Public Economy Department of the canton of Neuchâtel, Switzerland. It is located in the city of Neuchâtel and was founded in 1858. The first director was the German born, ...

) and 1924 (final section:

Algiers Observatory The Algiers Observatory was built in the late 19th century in the Algiers suburb of Bouzaréah, Algeria, North Africa. It participated in the Astrographic Catalogue project, taking the zone between -2 and +4 degrees to expose 1,260 plates betwe ...

), listing 200 000 stars down to ninth

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

. The second version, AGK2, was started in the 1920s, and published between 1951 and 1958 using photographic data obtained from the

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

and Hamburg Observatories.

Karl Friedrich Küstner Karl Friedrich Küstner (born in Görlitz on 22 August 1856, died 15 October 1936) was a German astronomer who also made contributions to Geodesy. In 1888, he reportedly discovered the Polar motion of the Earth. In 1910, he received the Gold Med ...

was involved in the planning for star catalog AGK2 with the Bonn part then directed by

Ernst Arnold Kohlschütter Ernst is both a surname and a given name, the German, Dutch, and Scandinavian form of Ernest. Notable people with the name include: Surname * Adolf Ernst (1832–1899) German botanist known by the author abbreviation "Ernst" * Anton Ernst (born ...

. The third version, AGK3, was started in 1956 and published in 1975. It contains 183,145 stars north of

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or ...

–2° with mean positional errors of ±0.13 " and mean

proper motion Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable referenc ...

errors of ±0.009"/year.

References

DavidDarling.info

Astro.it

External links

AGK3 query form from VizieR
Astronomical catalogues of stars {{astronomical-catalogue-stub

History

See also

References

External links