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. Histor ...

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 years, ...

. Compilation for the first version, AGK1, was started in 1861 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 and 1954, 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 The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ruhr r ...

and Hamburg Observatories. 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. Declination's angle is measured north or south of the ...

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

proper motion Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...

errors of ±0.009"/year.

References

DavidDarling.info

Astro.it

External links

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

See also

References

External links