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, and this article covers only some of the more frequently quoted ones. Star catalogues were compiled by a number of different ancient people, including the Babylonians, Greeks, Chinese, Persians, and Arabs. They were sometimes accompanied by a star chart for illustration. Most modern catalogues are available in electronic format and can be freely downloaded from space agencies' data centres. The largest is being compiled from the spacecraft Gaia and thus far has over a billion stars.
Completeness and accuracy are described by the faintest limiting magnitude V (largest number) and the accuracy of the positions.
Historical catalogues
Ancient Near East From their existing records, it is known that the ancient Egyptians recorded the names of only a few identifiable constellations and a list of thirty-six decans that were used as a star clock. The Egyptians called the circumpolar star "the star that cannot perish" and, although they made no known formal star catalogues, they nonetheless created extensive star charts of the night sky which adorn the coffins and ceilings of tomb chambers.
Although the ancient Sumerians were the first to record the names of constellations on clay tablets, the earliest known star catalogues were compiled by the ancient Babylonians of Mesopotamia in the late 2nd millennium BC, during the Kassite Period (). They are better known by their Assyrian-era name 'Three Stars Each'. These star catalogues, written on clay tablets, listed thirty-six stars: twelve for "Anu" along the celestial equator, twelve for "Ea" south of that, and twelve for "Enlil" to the north. The Mul.Apin lists, dated to sometime before the Neo-Babylonian Empire (626–539 BC), are direct textual descendants of the "Three Stars Each" lists and their constellation patterns show similarities to those of later Greek civilization.
Hellenistic world and Roman Empire In Ancient Greece, the astronomer and mathematician Eudoxus laid down a full set of the classical constellations around 370 BC. His catalogue Phaenomena, rewritten by Aratus of Soli between 275 and 250 BC as a didactic poem, became one of the most consulted astronomical texts in antiquity and beyond. It contained descriptions of the positions of the stars and the shapes of the constellations, and provided information on their relative times of rising and setting.
Approximately in the 3rd century BC, the Greek astronomers Timocharis of Alexandria and Aristillus created another star catalogue. Hipparchus () completed his star catalogue in 129 BC, the earliest known attempt to map the entire sky, which he compared to Timocharis' and discovered that the longitude of the stars had changed over time. This led him to determine the first value of the precession of the equinoxes. In the 2nd century, Ptolemy () of Roman Egypt published a star catalogue as part of his Almagest, which listed 1,022 stars visible from Alexandria. Ptolemy's catalogue was based almost entirely on an earlier one by Hipparchus.Newton 1977; Rawlins 1982 It remained the standard star catalogue in the Western and Arab worlds for over eight centuries. The Islamic astronomer al-Sufi updated it in 964, and the star positions were redetermined by Ulugh Beg in 1437, but it was not fully superseded until the appearance of the thousand-star catalogue of Tycho Brahe in 1598.
The ancient Vedic and other scriptures of India were well aware of the astronomical positions and constellations. Both Mahabharata and Ramayana provide references to various events in terms of the planetary positions and constellations of that time. The Planetary positions at the time of Mahabharata war has been given comprehensively. A discussion about the planetary positions along with specific name of constellations appears in a paper by R N Iyengar in the Indian Journal of History of Science.
Ancient China
The earliest known inscriptions for Chinese star names were written on oracle bones and date to the Shang dynasty (). Sources dating from the Zhou dynasty ( – 256 BC) which provide star names include the Zuo Zhuan, the Shi Jing, and the "Canon of Yao" (堯典) in the Book of Documents. The Lüshi Chunqiu written by the Qin statesman Lü Buwei () provides most of the names for the twenty-eight mansions (i.e. asterisms across the ecliptic belt of the celestial sphere used for constructing the calendar). An earlier lacquerware chest found in the Tomb of Marquis Yi of Zeng (interred in 433 BC) contains a complete list of the names of the twenty-eight mansions. Star catalogues are traditionally attributed to Shi Shen and Gan De, two rather obscure Chinese astronomers who may have been active in the 4th century BC of the Warring States period (403–221 BC). The Shi Shen astronomy (石申天文, Shi Shen tienwen) is attributed to Shi Shen, and the Astronomic star observation (天文星占, Tianwen xingzhan) to Gan De.
It was not until the Han dynasty (202 BC – 220 AD) that astronomers started to observe and record names for all the stars that were apparent (to the naked eye) in the night sky, not just those around the ecliptic. A star catalogue is featured in one of the chapters of the late 2nd-century-BC history work Records of the Grand Historian by Sima Qian (145–86 BC) and contains the "schools" of Shi Shen and Gan De's work (i.e. the different constellations they allegedly focused on for astrological purposes). Sima's catalogue—the Book of Celestial Offices (天官書 Tianguan shu)—includes some 90 constellations, the stars therein named after temples, ideas in philosophy, locations such as markets and shops, and different people such as farmers and soldiers. For his Spiritual Constitution of the Universe (靈憲, Ling Xian) of 120 AD, the astronomer Zhang Heng (78–139 AD) compiled a star catalogue comprising 124 constellations. Chinese constellation names were later adopted by the Koreans and Japanese.
Islamic world A large number of star catalogues were published by Muslim astronomers in the medieval Islamic world. These were mainly Zij treatises, including Arzachel's Tables of Toledo (1087), the Maragheh observatory's Zij-i Ilkhani (1272), and Ulugh Beg's Zij-i Sultani (1437). Other famous Arabic star catalogues include Alfraganus' A compendium of the science of stars (850) which corrected Ptolemy's Almagest; and al-Sufi's Book of Fixed Stars (964) which described observations of the stars, their positions, magnitudes, brightness, and colour, drawings for each constellation, and the first known description of the Andromeda Galaxy. Many stars are still known by their Arabic names (see List of Arabic star names).
Pre-Columbian Americas The Motul Dictionary, compiled in the 16th century by an anonymous author (although attributed to Fray Antonio de Ciudad Real), contains a list of stars originally observed by the ancient Mayas. The Maya Paris Codex also contains symbols for different constellations which were represented by mythological beings.
Bayer and Flamsteed catalogues
Two systems introduced in historical catalogues remain in use to the present day. The first system comes from the German astronomer Johann Bayer's Uranometria, published in 1603 and regarding 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. The major problem with Bayer's naming system was the number of letters in the Greek alphabet (24). It was easy to run out of letters before running out of stars needing names, particularly for large constellations such as Argo Navis. Bayer extended his lists up to 67 stars by using lower-case Roman letters ("a" through "z") then upper-case ones ("A" through "Q"). Few of those designations have survived. It is worth mentioning, however, as it served as the starting point for variable star designations, which start with "R" through "Z", then "RR", "RS", "RT"..."RZ", "SS", "ST"..."ZZ" and beyond.
The second system comes from the English astronomer John Flamsteed's Historia coelestis Britannica (1725). It kept the genitive-of-the-constellation rule for the back end of his catalogue names, but used numbers instead of the Greek alphabet for the front half. Examples include 61 Cygni and 47 Ursae Majoris.
Full-sky catalogues (in chronological order) 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, billions of stars resolvable by 21st century telescopes, so this is an impossible goal; with this kind of catalog, an attempt is generally made to get every star brighter than a given magnitude.
LAL
Jérôme Lalande published the Histoire céleste française in 1801, which contained an extensive star catalog, among other things. The observations made were made from the Paris Observatory and so it describes mostly northern stars. This catalogue contained the positions and magnitudes of 47,390 stars, out to magnitude 9, and was the most complete catalogue up to that time. A significant reworking of this catalogue by followers of Lalande in 1846 added reference numbers to the stars that are used to refer to some of these stars to this day. The decent accuracy of this catalogue kept it in common use as a reference by observatories around the world throughout the 19th century.
BD/CD/CPD
The Bonner Durchmusterung (German: Bonn sampling) and follow-ups were the most complete of the pre-photographic star catalogues.
The Bonner Durchmusterung itself was published by Friedrich Wilhelm Argelander, Adalbert Krüger, and Eduard Schönfeld between 1852 and 1859. It covered 320,000 stars in epoch 1855.0.
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 (see next entry) 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 towards zero, 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.
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 Charles Pickering, and was named in honour of Henry Draper, whose widow donated the money required to finance it.