astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

, Durchmusterung or Bonner Durchmusterung (BD) 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. His ...

star catalogue of the whole sky, compiled by 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-Ru ...

Observatory in Germany from 1859 to 1903. The name comes from ('run-through examination'), a German word used for a systematic survey of objects or data. The term has sometimes been used for other astronomical surveys, including not only stars, but also the search for other celestial objects. Special tasks include celestial scanning in electromagnetic wavelengths shorter or longer than

visible light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...

waves.

Original catalog

The 44 years of work on the Bonner Durchmusterung (abbreviated BD), initiated 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 largely carried out by his assistants, resulted in a catalogue of the positions and

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

s of approximately 325,000 stars to apparent magnitude 9–10. The catalogue was accompanied by charts plotting the positions of the stars, and was the basis for the '' Astronomische Gesellschaft Katalog'' (AGK) and ''

Smithsonian Astrophysical Observatory Star Catalog The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue, created by Smithsonian Institution, a research institute. It was published by the Smithsonian Astrophysical Observatory in 1966 and contains 258,997 stars. T ...

'' (SAO) catalogues of the 20th century. The BD star numbers are still used and allow the correlation of the work with modern projects. The format of a BD number is exemplified by "BD−16 1591", which is the BD number of

Sirius Sirius is the brightest star in the night sky. Its name is derived from the Greek word , or , meaning 'glowing' or 'scorching'. The star is designated α Canis Majoris, Latinized to Alpha Canis Majoris, and abbreviated Alpha CM ...

. This number signifies that in the catalog, Sirius is the 1591st star listed in the declination zone between −16 and −17 degrees, counting from 0 hours right ascension. Stellar positions and zone boundaries use an

equinox A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and se ...

for the epoch of B1855.0.

Extension

Many astronomical research projects—from studies of

celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, to ...

and the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

, up to the nascent field of astrophysics—were made possible by the publication of the atlas and data of the Bonner Durchmusterung. However, a deficiency of the BD was that it did not cover the whole sky, because far southern stars are not visible from Germany. This led the scientific community to supplement the BD with two additional astrometric surveys carried out by

observatories An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

located in the Southern Hemisphere: Córdoba, Argentina, and

Cape Town Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...

, South Africa. The Cordoba Durchmusterung (abbreviated CD, or, less commonly, CoD) was made visually (as was the BD), but the Cape Photographic Durchmusterung (CP or CPD) was conducted by the then-new photographic technique, which had just been shown to have sufficient accuracy. The southern stars are identified by CD and CPD numbers in a manner similar to the BD numbering system. A few decades later, the positional accuracy of the Durchmusterung catalogues began to be insufficient for many projects. To establish a more exact reference system for the Bonner Durchmusterung, astronomers and

geodesist Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equival ...

s began to work on a fundamental

celestial coordinate system Astronomical coordinate systems are organized arrangements for specifying positions of satellites, planets, stars, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true hor ...

based on the

Earth's rotation axis In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbit ...

, the vernal

and the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

plane in the late 19th century. This astrometric project led to the ''

Catalogues of Fundamental Stars The Catalogue of Fundamental Stars is a series of six astrometric catalogues of high precision positional data for a small selection of stars to define a celestial reference frame, which is a standard coordinate system for measuring positions of ...

'' of the Berlin observatory, and was used as an exact coordinate frame for the BD and AGK. It was modernized in the 1920s ( FK3, mean accuracy ±1″), and in 2000 ( FK6, accuracy 0.1″) as successive steps of cosmic geodesy. Together with radioastronomical measurements, the FK6 accuracy was better than ±0.1″.

Modern counterparts

The '' Hipparcos'' satellite operated between 1989 and 1993 and observed around 118,000 stars over the whole sky. Three star catalogues were published from its data: * ''

Hipparcos Catalogue ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial ...

'' (118,000 stars, average accuracy ±0.001″) * '' Tycho Catalogue'' (about 1,050,000 stars, with accuracy ±0.03″) * ''

Tycho-2 Catalogue The Tycho-2 Catalogue is an astronomical catalogue of more than 2.5 million of the brightest stars. Catalogue The astrometric reference catalogue contain positions, proper motions, and two-color photometric data for 2,539,913 of the brigh ...

'' (about 2,500,000 stars), which was improved for double star effects and proper motions using the

Astrographic Catalogue The Carte du Ciel (literally, 'Map of the Sky') and the Astrographic Catalogue (or Astrographic Chart) were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue an ...

observations. The '' Gaia''

space observatory A space telescope or space observatory is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launche ...

, launched in December 2013, has catalogued a billion stars with an accuracy down to 20 microarcseconds (0.00002″).

References

External links

Bonner Durchmusterung (Argelander 1859–1862)
(clicking on "bd.gz" downloads the gzipped 10.1MB catalogue)
Cordoba Durchmusterung (Thome 1892–1932)
(clicking on "cd.dat.gz" downloads the gzipped 19MB catalogue) (note: the extension might have to be removed with some text editor before opening)
Cape Photographic Durchmusterung (Gill+ 1895–1900)
(clicking on "cpd.dat.gz" downloads the gzipped 14.1MB catalogue) (note: the extension might have to be removed with some text editor before opening) {{Portal bar, Astronomy, Stars, Spaceflight, Outer space, Solar System Astronomical catalogues Astronomical catalogues of stars Astronomical surveys

Original catalog

Extension

Modern counterparts

References

Further reading

External links