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In astronomy, Durchmusterung is the usual name for three comprehensive astrometric star catalogues of the whole sky, processed by the Bonn Observatory (Germany) from 1859 to 1903, named the Bonner Durchmusterung. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study Astrometry is the branch of Astronomy that relates to precise measurements and explanations of the positions and movements of Stars and other celestial bodies A star catalogue, or star catalog, is an Astronomical catalogue that lists Stars In Astronomy, many stars are referred to simply by catalogue [1] Today the term Durchmusterung includes not only stars but also the search for other celestial objects. Special tasks are the celestial scanning in electromagnetic wavelengths which are shorter or longer than light waves. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 The name comes from Durchmusterung, a German word for a systematic survey of objects or data. Systematic was a Hard rock band from San Jose California. The band was one of the first signings to Metallica drummer Lars Ulrich 's

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Original

The 44 years work of the Bonner Durchmusterung (abbreviated by BD) tabulates the positions and apparent magnitudes of approximately 325,000 stars to apparent magnitude 9–10. The apparent magnitude ( m) of a celestial body is a measure of its Brightness as seen by an observer on Earth, normalized to the value It was the basis for an excellent star atlas (some 100 pages) and for the AGK and SAO catalogues of the 20th century. The Astronomische Gesellschaft Katalog (AGK is an Astrometric Star catalogue. The Smithsonian Astrophysical Observatory Star Catalog is an astrometric Star catalogue. The twentieth century of the Common Era began on The BD star numbers are still used and allow the correlation of this pioneering work with modern projects. A star number is a centered Figurate number that represents a centered Hexagram, such as the one that Chinese checkers is played on

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 with a visual Apparent magnitude of &minus1 The -16 component is the declination of Sirius, and 1591 a leaping number. [2]

Extension

Many astronomical projects — from studies of celestial mechanics and the solar system, up to the nascent field of astrophysics — were essentially supported by Atlas and data of the Bonner Durchmusterung. Celestial mechanics is the branch of Astrophysics that deals with the motions of Celestial objects The field applies principles of Physics, historically The Solar System consists of the Sun and those celestial objects bound to it by Gravity. Astrophysics is the branch of Astronomy that deals with the Physics of the Universe, including the physical properties ( Luminosity, But some decades later the positional accuracy began to be insufficient for more exact projects. Further the BD could not cover the whole sky, because far southern stars are not visible from Germany. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.

So the scientific community decided to supplement the Southern Sky by two additional astrometric surveys which should be carried out by observatories located at the Southern hemisphere: Córdoba, Argentina, and Cape Town, South Africa. The scientific community consists of the total body of Scientists its relationships and interactions An observatory is a location used for observing terrestrial and/or celestial events Southern Hemisphere is the half of a Planet that is South of the Equator —the word hemisphere literally means 'half ball' Córdoba, abbreviated as CBA, is a city located near the geographical center of Argentina, in the foothills of the Sierras Chicas mountains on the For a topic outline on this subject see List of basic Argentina topics. Cape Town (Kaapstad Xhosa: Ikapa) is the second most populous city in South Africa, forming part of the metropolitan municipality of the The Republic of South Africa (also known by other official names) is a country located at the southern tip of the continent of Africa The Cordoba Durchmusterung (abbreviated CD) was made visually — similar to the former BD), but the Cape Photographic Durchmusterung (CPD) was conducted by the new photographic technique, which just before was shown to have sufficient accuracy. In Astronomy, Durchmusterung or Bonner Durchmusterung ( BD) is the usual name for three comprehensive astrometric Star catalogues The visual system is the part of the Nervous system which allows organisms to see. In Astronomy, Durchmusterung or Bonner Durchmusterung ( BD) is the usual name for three comprehensive astrometric Star catalogues Photography (fә'tɒgrәfi or fә'tɑːgrәfi (from Greek φωτο and γραφία is the process and Art of recording pictures by means of capturing Similar to the BD numbers, the southern stars are identified by CD and CPD numbers. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth

To establish a more exact reference system for the Bonner Duchmusterung, in the late 19th century the astronomers and geodesists began to work on a Celestial Fundamental Co-ordinate System, based on the Earth's rotation axis, the vernal equinox and the Ecliptic plane. In general a reference is a relation between objects in which one object designates by linking to another object The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Geodesy (dʒiːˈɒdɪsi also called geodetics, a branch of Earth sciences, is the scientific discipline that deals Rotation period Earth's rotation period relative to the Sun (its mean solar day is 86400 Seconds of mean solar time An equinox is the event of the Sun passing over the Earth's equator in its annual cycle The ecliptic is the apparent path that the Sun traces out in the sky during the year This astrometric project led to the Fundamental Catalogue of the Berlin observatory and was used as an exact coordinate frame for the BD and AGK. Berlin is the capital city and one of sixteen states of Germany. It was modernized in the 1920s (FK3, mean accuracy ±1"), up to the present FK6 as the latest step of cosmic geodesy (accuracy 0. 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 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 1"). Together with radioastronomical measurements the FK6 accuracy is now better than ±0. 1".

Modern counterparts

Parallel to this, some astrometric satellites were planned to revolve round the Earth. The most important result of these developments was the Hipparcos space probe which scanned 108,000 stars over the whole sky by a network of thousands of CCD cross profiles and led to three very accurate star catalogues:

In the next decade a further step is planned using a future satellite, Gaia. Gaia is a European Space Agency (ESA Astrometry space mission and a successor to the ESA Hipparcos mission The Gaia catalogue plans to have at least 10 times more stars than Tycho II, with an apparent magnitude limit of 13 or fainter. Therefore will include a sufficient number of stars of our Galaxy to make future projects more relevant for the extreme accuracy of modern space science. The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Γαλαξίας (Galaxias sometimes referred to simply

References

  1. ^ Bonner Durchmusterung at VizieR Service, Centre de Données astronomiques de Strasbourg
  2. ^ BD query at Simbad database, Centre de Données astronomiques de Strasbourg
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