This guideline documents an English Wikipedia naming convention. It is a generally accepted standard that editors should attempt to follow, though it is best treated with common sense, and occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.

Shortcut: WP:NCASTRO

This page in a nutshell: This convention gives guidance on the names that should be used for articles on astronomical objects, from small solar system bodies to galaxy groups and clusters. Common names should be used where these are popular or otherwise the official names. Where there is a conflict between official names, a hierarchy of preference should be used according to the most common naming system. Redirect articles should be used wherever possible.

Contents 1 General guidelines 1.1 Common names 1.2 Reference information on astronomical names 1.3 Disambiguation 1.4 Capitalisation 2 Specific guidelines 2.1 Dwarf planets 2.2 Asteroids 2.2.1 Natural satellites of small solar system bodies 2.3 Comets 2.4 Stars 2.5 Extrasolar planets 2.6 Galaxies 2.7 Groups and clusters of galaxies 3 Notes 4 See also

[edit] General guidelines

The policy Wikipedia:Naming conventions states:

Generally, article naming should give priority to what the majority of English speakers would most easily recognize, with a reasonable minimum of ambiguity, while at the same time making linking to those articles easy and second nature. Names of Wikipedia articles should be optimized for readers over editors; and for a general audience over specialists. Wikipedia determines the recognizability of a name by seeing what verifiable reliable sources in English call the subject.

[edit] Common names

See WP:COMMONNAME

Common names should be used for article names in preference to official names where these are widely used and are unambiguous.

[edit] Reference information on astronomical names

The SIMBAD website and the NASA/IPAC Extragalactic Database (NED) are both professional astronomy resources that can be used to check for accepted alternate designations for individual objects, including traditional names. However, neither website necessarily lists the designations in the order of most common use; the criteria below must still be applied. Note that SIMBAD countains broad information on objects inside and outside the Milky Way whereas NED primarily contains information on extragalactic objects (i.e. objects outside the Milky Way). Therefore, it is recommended that SIMBAD be used for checking the names of objects primarily within the Milky Way and that both SIMBAD and NED be used for checking names for objects outside the Milky Way. Also note that neither website contains any information on objects within the Solar System.

[edit] Disambiguation

In general, the official name of an object should be used (e.g. Jupiter). If another object shares a name with something more notable, the type of object should follow in parentheses. (e.g. Mercury (planet))

[edit] Capitalisation

As per the guideline Wikipedia:Naming conventions (capitalization), where a word such as "Group", "Cluster" or "Star" is part of the object's proper name, this should be capitalised in the article title.

[edit] Specific guidelines

[edit] Dwarf planets

As per the consensus established at Talk: Dwarf planet/Naming, the official name should be used for the article title. In situations where there are other notable objects sharing the same name, the disambiguation term "dwarf planet" should be used in parentheses after the name. An example of this would be Eris (dwarf planet). Regardless of the article title, the MPC catalogue number/name designation should be referenced in the lead sentence. Syntax of this is still debated, but should incorporate a link to the minor planet number article.

[edit] Asteroids

Articles about asteroids and other small solar system bodies (not including comets, which are addressed below) should be named as follows;

1. For bodies which have received official naming from the Minor Planet Center, the article title should be the object's official minor planet number without parentheses, followed by its name e.g. 4 Vesta.
2. Where a body has not yet received an official name, but has received a minor planet number, the article title should be the object's official minor planet number in parentheses, followed by the object's provisional designation. This provisional designation is usually the object's discovery year, followed by an alphanumeric code signifying exactly when within the year it was discovered e.g. (15760) 1992 QB1. Any use of the name other than the title should use proper subscripting, using the provided templates {{mp}} and {{mpl}} (e.g. {{mpl|(15760) 1992 QB|1}} yielding (15760) 1992 QB₁).
3. Where as body has neither received an official name nor minor planet number, the article's title should simply be the object's provisional designation as described above e.g. 2004 JG6 (written {{mp|2004 JG|6}} yielding 2004 JG₆).

Unofficial nicknames should not be used as article titles.

[edit] Natural satellites of small solar system bodies

(tbc)

[edit] Comets

Articles about comets should be named in the following preference.

1. For extremely famous comets which have no issues with disambiguation, these should be titled "Comet <name>", e.g. Comet Halley.
2. Other comets should be referred by their official designation in the new-style format (post 1994). This is usually;

• For numbered periodic comets; its periodic comet number, followed by P/ if still an active comet and D/ for comets which have broken up or been lost, then the name of the discoverer or co-discoverers separated by hyphens (with no space between the forward-slash and the name(s)). e.g. 153P/Ikeya-Zhang

• For unnumbered comets; P/ for periodic, C/ for comets in hyperbolic orbits, D/ for comets which have been destroyed and X/ for comets for which no reliable orbit has been calculated, followed by the year of discovery, then an alphanumeric code which describes when in the year the comet was discovered, then the name should be in parentheses. e.g. C/2001 Q4 (NEAT)

Note that as comets are named after their discoverer or discoverers, and that those people may discover more than one comet, using the 1st option above, i.e. "Comet <Name>" may be ambiguous in some circumstances. E.g. Comet Hyakutake may refer to C/1995 Y1 (Hyakutake) or C/1996 B2 (Hyakutake), although only latter became widely known. Care must therefore be taken if using only the first option above to avoid ambiguity.

[edit] Stars

Articles on stars should be named with the following preferences:

1. If the star has a traditional name that has been approved by International Astronomical Union and is more widely used than any other name, this name is to be the article's title (e.g. Vega, Sirius, Aldebaran).
2. If the traditional name is not approved by the IAU, or there is no traditional name, the Bayer designation is to be the article's title (e.g. Alpha Centauri, Delta Capricorni, Upsilon Andromedae).
3. If there is no Bayer designation, then the Flamsteed designation is to be the article's title (e.g 55 Cancri, 51 Pegasi, 61 Cygni).
4. If there is no Bayer or Flamsteed designation, then the Draper number (HD) and or Gliese number (GJ) should be the article's title based on which one is in wider use (e.g. HD 98800, GJ 3021, Gliese 876).
5. If there is no Bayer, Flamsteed, Draper, or Gliese designations, then the most widely recognised (other) name is to be the article's title (e.g GSC 02652-01324, 2M1207, Lalande 21185).

[edit] Extrasolar planets

As per the consensus established at Talk:Extrasolar planet/Naming, articles on extrasolar planets should be named according to the parent star's article title^[1] than the planetary designation (e.g. 51 Pegasi → 51 Pegasi b). All planetary designations are to be lowercase letters (excluding the planets of PSR B1257+12 and planets announced prior to 1995, which have uppercase letters). Unless the planet is purposely cataloged differently than its parent star (e.g. GSC 02652-01324 → TrES-1) should the planet article be named differently.

The issue on whether to ad a space between the parent star's name and the planetary designation is to be determined by scientific literature references. In most cases, planets named with Bayer, Flamsteed, and or Variable star designation would always have a space, but other designations are debatable. Either way is acceptable, but please use Google Scholar to determine which one is in more use (which in turn should be the article title).

Since the International Astronomical Union (IAU) states that unofficial nicknames (e.g. Bellerophon and Osiris) are not the officially recognized names, extrasolar planet articles should not be named this. These names are only to be mentioned in the article.

[edit] Galaxies

Articles on galaxies should be named according to the following criteria (in order of preferences):

1. Traditional name where approved by the International Astronomical Union and where this is widely used in general or professional literature (e.g. the Andromeda Galaxy)
2. The Messier object number (e.g. Messier 30)
3. The New General Catalogue number (e.g. NGC 1)
4. Any relatively unusual catalog name that is widely used in general or professional literature and that is more commonly used than the IC or UGC number (e.g. Arp 220, Mrk 33)
5. The Index Catalogue number (e.g. IC 2)
6. The Uppsala General Catalogue number (e.g. UGC 1)
7. The most commonly used scientific designation given by any other catalog

Note that traditional galaxy names are proper nouns. Therefore, all the words in the galaxy name should begin with capital letters. For example, "Andromeda Galaxy" is acceptable, but "Andromeda galaxy" is not.

[edit] Groups and clusters of galaxies

Articles of groups and clusters of galaxies should be named according to the following criteria (in order of preference):

1. Traditional name where approved by the International Astronomical Union and where this is widely used in general or professional literature (e.g. the Local Group, Virgo Cluster, Stephan's Quintet)
2. Name based on the brightest galaxy in the group when that name is commonly used for identification (e.g. the M81 Group); this is only applicable to groups of galaxies within approximately 50 Mpc
3. The most commonly-used catalog number (e.g. Abell 3266)

Note that group and cluster names are proper nouns. Therefore, all the words in the galaxy name should begin with capital letters. For example, "Virgo Cluster" is acceptable, but "Virgo cluster" is not.

[edit] Notes

[edit] See also

• Wikipedia:Naming conventions
• Astronomical naming conventions