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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, and this article covers only some of the more frequently quoted ones. Most of the recent catalogues are available in electronic format and can be freely downloaded from NASA's Astronomical Data Center and other places (see links at end).
Although no longer in serious use, mention should be made of Ptolemy's star catalogue published in the 2nd century as part of his Almagest, which lists 1,022 stars visible from Alexandria. It was the standard star catalogue in the Western and Arab worlds for over a thousand years. Ptolemy's catalogue was based almost entirely on an earlier one by Hipparchus from the 2nd century B.C. (Newton 1977; Rawlins 1982). An even earlier star catalogue was that of Timocharis of Alexandria, which was written about 300 B.C. and later used by Hipparchus.
Two systems introduced in historical catalogues remain in use to the present day. The first system comes from Bayer's Uranometria and is for bright stars. These are given a Greek letter followed by the genitive case of the constellation in which they are located; examples are Alpha Centauri or Gamma Cygni. See Bayer designation for more information. The major problem with Bayer's naming system was the number of letters in the Greek alphabet. It was easy to run out of letters before running out of stars needing names, particularly for large constellations such as Argo Navis.
The second system comes from John Flamsteed's Historia coelestis Britannica . It kept the genitive-of-the-constellation rule for the back end of his catalog names, but used numbers instead of the Greek alphabet for the front half. Examples include 61 Cygni and 47 Ursae Majoris; see Flamsteed designation for more information.
- Newton, Robert R. (1977). The Crime of Claudius Ptolemy. Baltimore: Johns Hopkins University Press.
- Rawlins, Dennis (1982). An investigation of the ancient star catalog. Pub. Astron. Soc. Pacific 94, 359.
Bayer and Flamsteed covered only a few thousand stars between them. In theory, full-sky catalogues try to list every star in the sky. There are, however, literally hundreds of millions, even billions of stars resolvable by telescopes, so this is an impossible goal; these kind of catalogs generally try to get every star brighter than a given magnitude.
HD / HDE
The Henry Draper Catalogue was published in the period 1918–1924. It covers the whole sky down to about ninth or tenth magnitude, and is notable as the first large-scale attempt to catalogue spectral types of stars. The catalogue was compiled by Annie Jump Cannon and her co-workers at Harvard College Observatory under the supervision of Edward Pickering, and was named in honour of Henry Draper, whose widow donated the money required to finance it.
HD numbers are widely used today for stars which have no Bayer or Flamsteed designation. Stars numbered 1–225300 are from the original catalogue and are numbered in order of right ascension for the 1900.0 epoch. Stars in the range 225301–359083 are from the 1949 extension of the catalogue. The notation HDE can be used for stars in this extension, but they are usually denoted HD as the numbering ensures that there can be no ambiguity.
The Smithsonian Astrophysical Observatory catalogue is a photographic atlas of the sky, complete to about ninth magnitude, as a result of which there is considerable overlap with the Henry Draper catalogue. The epoch for the position measurements in the latest edition is J2000.0. The SAO catalogue contains one more major piece of information than Draper, the proper motion of the stars, so it is often used when that fact is of importance. The cross-references with the Draper and Durchmusterung catalogue numbers in the latest edition are also useful.
Names in the SAO catalogue start with the letters SAO, followed by a number. The numbers are assigned following 18 ten-degree bands in the sky, with stars sorted by right ascension within each band.
The Bonner Durchmusterung and follow-ups were the most complete of the pre-photographic star catalogues.
As it covered only the northern sky and some of the south (being compiled from the Bonn observatory), this was then supplemented by the Südliche Durchmusterung (SD), which covers stars between declinations -1 and -23 degrees (1886, 120,000 stars). It was further supplemented by the Cordoba Durchmusterung (580,000 stars), which began to be compiled at Córdoba, Argentina in 1892 under the initiative of John M. Thome and covers declinations -22 to -90. Lastly, the Cape Photographic Durchmusterung (450,000 stars, 1896), compiled at the Cape, South Africa, covers declinations -18 to -90.
Astronomers preferentially use the HD designation of a star, as that catalogue also gives spectroscopic information, but as the Durchmusterungs cover more stars they occasionally fall back on the older designations when dealing with one not found in Draper. Unfortunately, a lot of catalogues cross-reference the Durchmusterungs without specifying which one is used in the zones of overlap, so some confusion often remains.
Star names from these catalogues include the initials of which of the four catalogues they are from (though the Southern follows the example of the Bonner and uses BD; CPD is often shortened to CP), followed by the angle of declination of the star (rounded down, and thus ranging from +00 to +89 and -00 to -89), followed by an arbitrary number as there are always thousands of stars at each angle. Examples include BD+50°1725 or CD-45°13677.
The Catalogue astrographique (Astrographic Catalogue) was part of the international Carte du ciel programme designed to photograph and measure the positions of all stars brighter than magnitude 11.0. In total, over 4.6 million stars were observed, many as faint as 13th magnitude. This project was started in the late 1800s. The observations were made between 1891 and 1950. To observe the entire celestial sphere without burdening only a handful of institutions, the sky was divided among 20 observatories, by declination zones. Each observatory exposed and measured the plates of its zone, using a standardized telescope so each plate photographed had a similar scale of approximately 60 arcsecs/mm. The U.S. Naval Observatory took over custody of the catalogue, now in its 2000.2 edition.
USNO-B1.0 is an all-sky catalog created by researchers at the U.S. Naval Observatory that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,042,618,261 objects derived from 3,643,201,733 separate observations. The data were obtained from scans of 7,435 Schmidt plates taken for the various sky surveys during the last 50 years. USNO-B1.0 is believed to provide all-sky coverage, completeness down to V = 21, 0.2 arcsecond astrometric accuracy at J2000.0, 0.3 magnitude photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from non-stellar objects.
- New general catalogue of double stars within 120 deg of the North Pole (1932, R. G. Aitken).
This lists 17,180 double stars north of declination -30 degrees.
BS / BSC / HR
First published in 1930 as the Yale Catalog of Bright Stars, this catalog contained information on all stars brighter than visual magnitude 6.5 in the Harvard Revised Photometry Catalogue. The list was revised in 1983 with the publication of a supplement that listed additional stars down to magnitude 7.1. The catalog detailed each star's coordinates, proper motions, photometric data, spectral types, and other useful information.
GJ / Gliese / Gl
The Gliese (later Gliese-Jahreiss ) catalogue attempts to list all stars within 20 parsecs of Earth (later editions expanded the coverage to 25 parsecs). Numbers in the range 1.0–965.0 are from the second edition, which was
- Catalogue of Nearby Stars (1969, W. Gliese).
Apparently, the integers represent stars which were in the first edition, while the numbers with a decimal point were used to insert new stars for the second edition without destroying the desired order. This catalogue is referred to as CNS2, although this name is never used in catalogue numbers.
Numbers in the range 9001–9850 are from the supplement
Numbers in the ranges 1000–1294 and 2001–2159 are from the supplement
- Nearby Star Data Published 1969–1978 (1979, W. Gliese and H. Jahreiss).
The range 1000–1294 represents nearby stars, while 2001–2159 represents suspected nearby stars.
Numbers in the range 3001–4388 are from
- Preliminary Version of the Third Catalogue of Nearby Stars (1991, W. Gliese and H. Jahreiss).
Although this version of the catalogue was termed "preliminary", it is still the current one as of September 2001, and is referred to as CNS3. It lists a total of 3,803 stars. Most of these stars already had GJ numbers, but there were also 1,388 which were not numbered (plus the Sun, which needs no number). The need to give these 1,388 some name has resulted in them being numbered 3001–4388, and data files of this catalogue now usually include these numbers. An example of a star which is often referred to by one of these unofficial GJ numbers is GJ 3021 (see Extrasolar planet).
The General Catalogue of Trigonometric Parallaxes, first published in 1952 and later superseded by the New GCTP (now in its fourth edition), covers nearly 9,000 stars. Unlike the Gliese, it does not cut off at a given distance from the Sun; rather it attempts to catalogue all known measured parallaxes. It gives the co-ordinates in 1900 epoch, the secular variation, the proper motion, the weighted average absolute parallax and its standard error, the number of parallax observations, quality of interagreement of the different values, the visual magnitude and various cross-identifications with other catalogues. Auxiliary information, including UBV photometry, MK spectral types, data on the variability and binary nature of the stars, orbits when available, and miscellaneous information to aid in determining the reliability of the data are also listed.
- William F. van Altena , John Truen-liang Lee and Ellen Dorrit Hoffleit, Yale University Observatory, 1995.
The Hipparcos catalogue was compiled from the data gathered by the European Space Agency's astrometric satellite Hipparcos, which was operational from 1989 to 1993. The catalogue was published in June 1997 and contains 118,218 stars. It is particularly notable for its parallax measurements, which are considerably more accurate than those produced by ground-based observations.
Proper motion catalogues
- Ross, Frank Elmore, New Proper Motion Stars, eleven successive lists, Astrophysical Journal, Vol. 36 to 48, 1925-1939
- Wolf, Max, "Katalog von 1053 stärker bewegten Fixsternen", Veröff. d. Badischen Sternwarte zu Heidelberg (Königstuhl), Bd. 7, No. 10, 1919; and numerous lists in Astron. Nachr. 209 to 236, 1919-1929
Willem Jacob Luyten later produced a series of catalogues:
L - Luyten, Proper motion stars and White dwarfs
- Luyten, W. J., Proper Motion Survey with the forty-eight inch Schmidt Telescope, University of Minnesota, 1941 (General Catalogue of the Bruce Proper-Motion Survey)
LFT - Luyten Five-Tenths catalogue
- Luyten, W. J., A Catalog of 1849 Stars with Proper Motion exceeding 0.5" annually, Lund Press, Minneapolis (Mn), 1955 ()
LHS - Luyten Half-Second Catalogue
- Luyten, W. J., Catalogue of stars with proper motions exceeding 0"5 annually, University of Minnesota, 1979 ()
LTT - Luyten Two-Tenths catalogue
- Luyten, W. J., Catalogue of stars with proper motions exceeding 0"2 annually, Univ. of Minnesota, 1980 ()
LP - Luyten Palomar proper-motion catalogue
- Luyten, W. J., Proper Motion Survey with the 48 inch Schmidt Telescope, University of Minnesota, 1963-1981
Later, Henry Lee Giclas took over, again with a series of catalogues:
- NASA Astronomy Data Center
- Centre de Données astronomiques de Strasbourg
- Sloan Digital Sky Survey
- IAU FAQ on "Naming Stars"
- Name a Star? The Truth about Buying Your Place in Heaven
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