Nomenclature (astronomy)

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In ancient times only the sun and moon, as well as a few hundred stars and the most easily visible planets were given names. Over the past hundred years, the number of identified astronomical objects has increased from hundreds to over a billion and more are discovered each year. Astronomers must be able to assign systematic names in order to identify all of them on their own and, on the other hand, to name objects of interest and, if relevant, also the features on these objects.

The International Astronomical Union (IAU) is a society officially recognized by astronomers and other scientists as the de facto naming authority for celestial objects. In response to the need for unique names, she produced some systematic naming systems for various celestial bodies.

Star names

According to the IAU, stars - other than a number of bright stars with historical names - have no proper names . If historical names exist, they come from the Arabic language , with a few exceptions , because the Arabs were leaders at the beginning of modern astronomy. See list of star names for examples.

There are several thousand stars in the earthly sky sufficiently bright to be visible to the naked eye, which set the limit to the possible number of stars that could be named by ancient cultures. This limit is approximate as it depends on the visual acuity of each observer, but tens of thousands of stars (the stars that can be seen with the naked eye up to the sixth visible brightness ) seem to form an upper limit to what is physiologically possible.

Estimates of the stars with known names are between 300 and 350. These are usually the brightest stars in the sky or stars that form parts of constellations . The number of proper names of stars is greater than the number of stars with proper names because different cultures named stars independently of each other. z. B. was the star known as Pole Star , at different times and in different places under the names Al-Ruccabah, Angel-Star, Attraction, the Guiding Star, Mismar, Navigatorie, Phonice, the Pole Star, the Star of Arcady , Tramontana or Yılduz.

With the advent of more powerful telescopes, many more stars became visible - many more than could have been named. Instead, they were given names from various star catalogs . Older catalogs either assigned an arbitrary number to the object or used a simple systematic naming scheme, such as B. a combination of constellation names with the Greek letters . Multiple star catalogs meant that some stars had multiple names. z. B. the star with the Arabic name Rigil Kentaurus also has the Bayer designation Alpha Centauri .

As the resolving power of telescopes increased, it was discovered that numerous objects that were believed to be individual objects and that were too close together in the sky to be distinguished by the human eye turned out to be multiple star systems . These and other confusions emphasize the need to be very careful with the label. z. B. Rigil Kentaurus consists of three stars in a triple star system called Rigil Kentaurus A, B and C.

Many modern catalogs have been generated with computers and high-resolution, highly sensitive telescopes and describe a very large number of objects. Objects in these catalogs are typically placed at a very high resolution, and names are given to these objects based on their positions in the sky. As an example we give SDSSp J153259.96-003944.1 , whereby the abbreviation "SDSSp" shows that it is an object in the " Sloan Digital Sky Survey preliminary objects". The other characters indicate the celestial coordinates .

The closest star, our sun , is typically simply referred to as the "sun" or as this word is called in other languages, e.g. B. sometimes in science fiction with its Latin name Sol.

Abbreviations of the star catalogs

The IAU is the supreme administrator of the namespace for astronomical terms in catalogs for astronomical objects. The purpose is to keep names given by the different catalogs unambiguous. There have been many historical star catalogs, and new star catalogs continue to be created regularly as new sky surveys are made. All names of objects in the last star catalogs begin with an abbreviation that the IAU keeps uniformly worldwide. Different star catalogs have different naming conventions for what comes after that abbreviation, but modern catalogs tend to follow a set of generic rules for the data formatting used.

Star naming

Several star naming firms are selling the right under whatever name the buyer wishes to list stars in their private registers. These companies typically deny the fact that they are not associated with scientific society and that such gifts are a novelty of a symbolic nature. The strong consumer demand for star naming gifts keeps these companies in business, even if they inform consumers well, but these names are not recognized as "official" by the IAU, and thus by most astronomers. Most astronomical (and international scientific) organizations say that the IAU is the only body that is officially allowed to name celestial objects. (In fact, companies overbook prominent stars with different names. Sometimes the same organization gives the same property different names. The customer is not informed of the previous naming.)

Constellation names and borders

The sky was arbitrarily divided into constellations by astronomers in history according to the perceived patterns in the sky. At first only the shapes of the patterns were determined, and the names and numbers of constellations varied from one star map to another. Although scientifically meaningless, they provide useful reference points for humans. In 1930 the constellation boundaries were determined by Eugène Joseph Delporte and adopted by the IAU, so that now every point on the celestial sphere belongs to a constellation.

Supernova names

Supernova discoveries are reported to the Central Office for Astronomical Telegrams of the International Astronomical Union , which publishes a circular with assigned names. The name is formed by the year of discovery, followed by a one to two letter designation. The first 26 supernovae of the year get the uppercase letters A to Z assigned. Thereafter, pairs of lowercase letters beginning with aa , ab etc. are used. Four historical supernovae are known simply by their year of discovery ( SN 1006 , 1054 , 1572 [Tycho Nova] and 1604 [Kepler's star]). The letters are used starting with the year 1885, even if only one supernova was discovered in that year (such as SN 1885A , 1907A ), the last being with SN 1947A . The standard abbreviation "SN" is an optional prefix. As the instruments got better and the number of amateur and professional astronomers looking for them increased, more and more supernovae have been and are being discovered each year. There are currently at least 500 new discoveries per year. z. B. the last supernova in 2007 was the SN 2007va , indicating that it was the 572nd supernova discovered that year - a record year.

Galaxy names

Like stars, most galaxies have no names. The Andromeda Galaxy or the Whirlpool Galaxy and others are exceptions, but most of them simply have catalog numbers.

In the 19th century, the exact number of galaxies was not yet clear, so the early catalogs simply grouped open clusters , globular clusters , nebulae and galaxies: the Messier catalog contains 110 objects. The Andromeda Galaxy is the Messier Object 31 or M 31 ; the vortex galaxy is M 51 .

The New General Catalog (NGC, JLE Dreyer 1888) was much larger and contained almost 8,000 objects, but nebulae, galaxies and star clusters were still cataloged and even unconfirmed objects were listed. Objects are identified with NGC and a serial number. Very similar terms from catalog abbreviations and a serial number can be found for objects from the index catalog IC and the Principal Galaxies Catalog PGC.

Planet names

The brightest planets in the sky were named in ancient times. The scientific names were taken from the Roman names: Mercury , Venus , Mars , Jupiter and Saturn . Our planet is commonly called Earth, or after its equivalent in any language (two French astronomers would call it la Terre ), however Earth has only recently been seen as a planet in history. The earth seen as a planet is sometimes also named with the Latin name Terra.

At least two other celestial bodies discovered later were called planets:

These celestial objects were given names from Greek or Roman mythology to match the ancient names, but only after some controversial discussion. z. B. Sir William Herschel discovered Uranus in 1781 and named it in honor of George III. originally Georgium Sidus (Georg's star). French astronomers first called him Herschel, before the German Johann Bode suggested the name Uranus after the Greek and Roman gods. This name caught on around 1850.

From 1801, asteroids were discovered between Mars and Jupiter. The first few ( Ceres , Pallas , Juno , Vesta ) were first considered planets. As more and more were discovered, they were stripped of their planetary status. On the other hand, Pluto was considered a planet in 1930 because it was beyond Neptune. According to this pattern, several hypothetical celestial bodies were given names: volcano for a planet within Mercury's orbit; Phaeton for a planet between Mars and Jupiter, believed to be the predecessor of the asteroids; Themis for a moon of Saturn; and Persephone, as well as several other names for a transplutonic planet.

These names, which come from classical mythology , are only seen as standard in Western discussions. Astronomers from other cultures with different traditional names may not use these names in scientific discourse. The IAU does not disapprove of astronomers who e.g. B. Discuss Jupiter, the Arabic nameالمشتري Al-Mushtarīy or use the Chinese name 海王星 Hǎiwángxīng for Neptune .

Approx. Sixty years after the discovery of Pluto, the discovery of large numbers of large Trans-Neptunian objects began. According to the criteria for how Kuiper Belt objects are classified, it became unclear whether Pluto would still have been considered a planet had it been discovered in the 1990s. Today we know that Pluto's mass is much smaller than once assumed and, together with Eris , forms one of the two largest Trans-Neptunian objects. In 2006, Pluto was therefore re- classified as a dwarf planet together with Eris and others .

Natural planetary moons

The Earth's moon is known simply as the moon or its equivalent in other languages ​​(such as la Lune in French ). Sometimes it is simply called Luna (Latin for "moon") in science fiction . Natural satellites from other planets are generally named after mythological figures, such as B. Uranus' satellites were named after characters from the works of William Shakespeare or Alexander Pope .

When new satellites are discovered, they are given provisional designations such as " S / 2010 J 2 " (the 2nd new satellite discovered by Jupiter in 2010) or " S / 2003 S 1 " (the 1st new satellite discovered by Saturn in 2003). The initial “S /” stands for “satellite” and distinguishes it from other prefixes such as “D /”, “C /” and “P /”, which are used for comets . The term "R /" is used for planetary rings. These names are sometimes used e.g. B. "S / 2003 S1" written by leaving out the second space. The letter to the category and year identifies the planet ( J Upiter, S aturn, U ranus, N eptun, although no new discoveries are expected in other planets, Mars and Mercury are indicated by the letter H distinguished ermes for the latter). Pluto was designated P prior to reclassification as a dwarf planet by the IAU . If the celestial object is found on a minor planet, its identifying number is used in brackets. So the moon of Ida , Dactyl , was first called " S / 1993 (243) 1 ". When it was confirmed and named, its name was (243) Ida I Dactyl . Similarly, Pluto’s fourth satellite was discovered Kerberos after Pluto was downgraded to a dwarf planet and given a minor planet number. Its designation was now S / 2011 (134340) 1 instead of S / 2011 P 1, although the New Horizons team , which did not agree with the dwarf planet classification, used the latter.

Note: The assignment of an "H" to Mercury was determined by the USGS Gazetteer of Planetary Nomenclature; although they usually closely follow IAU guidelines, it is very likely to be the IAU convention, but confirmation is required.

When, after a few years, the existence of a newly discovered satellite has been confirmed and its orbit has been calculated, a permanent name is determined, replacing the temporary designation with "S /" at the beginning. In the past, however, some satellites remained unnamed for a surprisingly long time after their discovery. The Roman numbering system came into being when the first natural satellite other than the moon was discovered: Galileo mentioned the Galilean moons as I through IV , counting from Jupiter outwards. He did this to annoy his rival Simon Marius , who suggested the names used today, after his own proposals to name these heavenly bodies after members of the Medici family were not accepted. Similar numbering methods emerged with the discovery of the moons around Saturn and Mars. Although the numbers were originally assigned sequentially according to the orbits of the satellites, this order got mixed up after the discovery of new objects (e.g. "Jupiter V" is the moon Amalthea , which orbits Jupiter in a narrower orbit than Io ). Thus, the unspoken convention at the end of the 19th century was that the numbers more or less reflected the order of discovery, except for the previous historical exceptions.

Geological and geographical characteristics of the planets and satellites

In addition to naming the planets and their satellites, geological and geographical features (mountains, craters, volcanoes, etc.) must be named on these celestial objects.

The IAU was founded in 1919, which commissioned a committee to standardize the chaotic technical terms common at the time. Most of the work was done by Mary Adela Blagg , and her and Muller's report entitled Named Lunar Formations in 1935 was the first systematic listing of lunar terms. Later, under the supervision of Gerard P. Kuiper, The System of Lunar Craters, quadrants I, II, III, IV was published. These works were adapted by the IAU and are now recognized sources for the technical terms relating to the moon.

The Mars terminology was cleared up in 1958 when an IAU committee suggested that the names of 128 luminance features observed by terrestrial telescopes be adopted. These names were based on a system of technical terms developed in the late 19th century by the Italian astronomer Giovanni V. Schiaparelli (1879) and expanded in the early 20th century by Eugène Michel Antoniadi (1929) who was an astronomer born in Greece and based in Meudon worked in France .

However, with the advent of space travel and space probes , high resolution images of various solar system objects became available and it became necessary to propose naming standards for the features visible on them.

Minor planets

Originally, the names of minor planets were given in the same way as other planets: names from Greek or Roman myths with a preference for female names. With the discovery of the first celestial body to cross orbit Mars in 1898, another choice was deemed appropriate and the name (433) Eros was given. This began with a naming pattern in which female names were given to main belt objects and male names to those with unusual orbits.

As more and more discoveries followed each year, this system was gradually felt to be unsuitable and a new one was developed. Currently, the main responsibility for assigning designations and names to minor planets is with the Committee for Small Body Nomenclature (CSBN), which consists of 15 people. If an object has been observed for at least two nights and cannot be identified with a known celestial object, minor planets are initially given a preliminary designation of the form "[[2001 KX 76 ]]" (the first part relates to the year of discovery; the second part defines a sequential one Order of discoveries this year). If a sufficient number of observations of this celestial body is known to calculate its orbit, it is assigned a sequential number - its 'name' - and can then use it as e.g. B. (28978) 2001 KX 76 .

After the designation has been assigned, the discoverer is given the opportunity to suggest a name which, if accepted by the IAU , will replace the provisional designation. This can take place after an observation period of two to three months. So got z. B. (28978) 2001 KX 76 named Ixion and is now named (28978) Ixion . The name became official after it was published in Minor Planet Circular with a short quote explaining its meaning. This can take place a few years after the first sighting, or as in the case of lost minor planets , it can take decades to be rediscovered and finally given a name. If a minor planet remains unnamed ten years after it was first named, the naming right is also granted to other people who have observed and reported other phenomena of this object.

In recent years, automatic observations such as LINEAR or LONEOS have discovered thousands upon thousands of new asteroids, so the CSBN has officially limited the number of objects to be named per person discovered to two per month. Therefore, the overwhelming majority of newly discovered asteroids have not been given a formal name at this time.

Under IAU rules, names must be pronounceable, and preferably one-word (such as (5535) Annefrank ), although exceptions are possible (such as (9007) James Bond ). Since 1982 the names including spaces and hyphens may not be longer than 16 characters, but there is one exception, namely (4015) Wilson-Harrington, who received this name in 1990 when his identity with the comet of the same name from 1949 was proven. Names with diacritical marks are accepted, although in English everyday use the diacritical marks are often ignored. (4090) Říšehvězd is an asteroid with the most (exactly four) diacritical marks. Military or political celebrities are inappropriate unless they have been dead for at least 100 years. Pet names are not recommended these days, but there are still some from the past. Names of people, companies or products that are only known for their business success are not accepted, nor are quotations that resemble advertisements.

Whimsical names can be used for relatively common asteroids (such as (26858) Misterrogers ), but names for those asteroids belonging to a particular dynamic group are expected to conform to the more strictly defined naming schemes.

Comets

Names given to comets have followed several different conventions over the past two centuries. Before any systematic naming convention was adopted, comets were named in various ways. The first comet to be named was " Halley's Comet ", now officially called Comet Halley and named after Edmond Halley , who calculated its orbit. Similarly, the second periodic comet called Comet Encke , formally called 2P / Encke, was named after the astronomer, Johann Franz Encke, who calculated its orbit, instead of its actual discoverer, Pierre Méchain . Other similarly named comets are “Biela's Comet” ( 3D / Biela ) and “Fräulein Herschel's Comet” ( 35P / Herschel – Rigollet or Comet Herschel – Rigollet). The brightest (non-periodic) comets were mentioned as "The great comet of ..." the year it appeared.

In the early 20th century, the convention of naming comets after those who discovered them was widely accepted and has remained so to this day. A comet is named after its first independent discoverer with up to three names separated by hyphens. The IAU prefers to honor a maximum of two explorers and only does this for more than three explorers if "in rare cases, lost comets are rediscovered and have been given a new name." In recent years, many comets have been through Discovered instruments controlled by large teams of astronomers. In this case, comets are named after the instrument (such as comet IRAS – Araki – Alcock (C / 1983 H1), which was discovered independently of the IRAS satellite and the amateur astronomers Genichi Araki and George Alcock ). Comet 105P / Singer Brewster , discovered by Stephen Singer-Brewster , should actually be called "105P / Singer-Brewster", but this could have been understood as a joint discovery by two astronomers named Singer and Brewster. That is why the hyphen was replaced by a space. The spaces, apostrophes and other characters in explorer names are retained in the comet names, such as 32P / Comas Solà , 6P / d'Arrest , 53P / Van Biesbroeck , Komet van den Bergh (1974g) , 66P / du Toit or 57P / du Toit – Neujmin – Delporte was the case.

Systematic naming of comets ("old style") was carried out until 1994 by first giving the comet a temporary name with the year of discovery followed by small letters. The small letters indicated the number of comet discovered that comet was in the year of discovery (e.g., according to this convention, comet was called Bennett 1969i because it was the 9th comet to be discovered that year). In 1987 more than 26 comets were discovered, so that the alphabet was used again from the beginning, similar to the asteroids with a subscript "1" (example: Comet Skorichenko – George , 1989e1). The record year was 1989, in which you came to 1989h1. Once an orbit was known, the comet was given a permanent name that corresponded to the sequence of the perihelion passages by adding a corresponding Roman number to the year. So was z. B. from Comet Bennett (1969i) Comet 1970 II .

An increasing number of comet discoveries made this procedure difficult to carry out, so in 2003 the Committee on Small Body Nomenclature recognized a new naming system and in 2004 approved a new naming system. Comets are now named after the year of discovery, followed by a letter that indicates the half-month of the discovery (A indicates the first half of January, B the second, C the first half of February, etc.) and a number that indicates the order of discovery. For example, the fourth comet, discovered in the second half of February, was named 2006 D4. The letters I and Z are not used for the month halves. Prefixes indicate the nature of the comet, where P / denotes a periodic, C / an aperiodic, and X / a comet with untrustworthy orbit data (such as comets in ancient chronicles). D / is used for comets that broke or disappeared, A / for comet that was first classified as a comet but later as an asteroid. As already mentioned, periodic comets have a number that indicates the order of their discovery. Bennett's comet is systematically referred to as C / 1969 Y1. The Halley's Comet , the first as a periodic comet is realized, has the systematic name P / 1682 Q1. The systematic name of comet Hale-Bopp is C / 1995 O1. The well-known Comet Shoemaker-Levy 9 was the ninth periodic comet jointly discovered by astronomers Carolyn Shoemaker , Eugene Shoemaker, and David Levy (the Shoemaker-Levy team also discovered four aperiodic comets among the periodic ones), but its systematic name is D / 1993 F2 (it was discovered in 1993 and given the prefix “D /” because it was observed to hit Jupiter ).

Some comets were first recognized as minor planets and were given a temporary name before comet-like activity was later discovered, such as: B. P / 1999 XN 120 (Catalina 2) or P / 2004 DO 29 (Spacewatch-LINEAR). The MPECs and HTML versions of the IAU catalogs and some other sources such as B. the Yamamoto circular and the Kometnyj Tsirkular use them.

Names of extrasolar planets

According to the IAU, there is currently no agreed system for naming planets that orbit other stars. The naming of exoplanets is organized by the Executive Committee Working Group Public Naming of Planets and Planetary Satellites of the IAU. The scientific term consists of a proper name or its abbreviation, followed by a small letter, such as B. in 51 Pegasi b .

See also

literature

Web links

Individual evidence

  1. ↑ Editorial: In Defense of Commercial Star Naming
  2. ^ List of Supernovae . Cbat.eps.harvard.edu. Retrieved August 17, 2012.
  3. ↑ cbat.eps.harvard.edu
  4. ↑ Categories (Themes) for Naming Features on Planets and Satellites ( English ) USGS Astrogeology Science Center. Retrieved September 15, 2019.
  5. ↑ a b c d Naming Astronomical Objects: Minor Planets ( English ) International Astronomical Union. Retrieved November 21, 2014.
  6. ↑ a b How Are Minor Planets Named? ( English ) Minor Planet Center. Retrieved November 21, 2014.
  7. ↑ a b c IAU Komet-naming Guidelines , Committee on Small Body Nomenclature of Division III of the IAU
  8. ^ Stan Gibilisco: Comets, meteors & asteroids - how they affect earth . 1st edition. Tab Books, Blue Ridge Summit, PA 1985, ISBN 0-8306-1905-4 , pp. 76 (English, limited preview in Google Book Search): “What if two or more different people discover the same comet at about the same time? This problem is solved by allowing a comet to bear as many as three names. The names are separated by hyphens. Thus we have had comets such as Ikeya-Seki and Arend-Roland. It has been decided that more than three names would be ridiculous and cumbersome. Therefore, we do not hear of comets such as Jones-Smith-James-Olson-Walters-Peterson-Garcia-Welch! "
  9. ↑ a b Don E. Machholz: comet corner . In: Association of Lunar and Planetary Observers (eds.): Journal of the Association of Lunar and Planetary Observers . tape 33 , no. 1 , 1989, pp. 25–28, 26 (English): “A hyphen (-) is used in a comet's name only to separate the discoverers. Thus, if sometimes the discoverer has a double name, the hyphen is dropped from the comet's name in order to show that there was only one discoverer. For example, in 1986 Stephen Singer-Brewster discovered a comet. It is known as 'comet Singer Brewster.' ”
  10. ↑ Cometary Designation System , IAU, first mentioned in Minor Planet Circulars 23803-4 , then in International Komet Quarterly 16, p. 127.
  11. ↑ [1] and [2] (PDF) of IAUC 8797, written there as P / 1999 DN 3 .
  12. ↑ See e.g. B.
  13. ↑ Naming of exoplanets ( English ) International Astronomical Union. Retrieved December 1, 2014.