Wikipedia:Notability (astronomical objects)

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This guideline is meant to reflect consensus about the notability of astronomical objects. The guideline covers all significant physical entities, associations or structures that current science has confirmed to exist in outer space. The guideline does not cover topics relating to artificial structures in space, such as artificial satellites, spacecraft, space probes, space stations or space telescopes. It also does not cover terrestrial locations, airspace, or material that has been transported to the Earth's atmosphere or surface, including moon rocks, meteor showers and meteorites.

Simply stated, an astronomical object is a body of matter (or collection of such bodies) that is bound together by a fundamental force, has boundaries defined by large-scale structure (e.g. voids), or is a combined grouping through viewing perspective (e.g. optical double stars). This includes galaxies, nebulae, star clusters, star systems, individual stars, planets, minor planets, asteroids, comets, and moons. It can also include bodies of matter that are held together by masses other than their own, such as a circumstellar disk, accretion disc, or zodiacal dust.

Basic notability[edit]

No inherent notability[edit]

Notable means "worthy of being noted" or "attracting notice". It is not synonymous with "fame" or "importance". Astronomical objects are notable if they have garnered a certain threshold of attention and analysis in the scientific literature and/or popular media. Famous astronomical objects are likely to have more readily available verifiable information from reliable sources that provide evidence of notability; however, more obscure objects can still be notable.

Even if editors personally believe an astronomical object is "important" or "inherently notable", astronomical objects are only accepted as notable if they have attracted notice in reliable sources. The fact that an astronomical object exists in space is by itself not enough to support notability. There exists a perennial debate on Wikipedia about the notability of geographic features, with no clear consensus; in practice all named geographic features (mountains, rivers, hills) are notable enough for an article. Some editors have included astronomical objects in the blanket category of geographic features, with the result being that it is acceptable for individual astronomical objects to be part of a list of similar objects. This notability guideline does not alter that practice with respect to lists. However, unlike Earth-based geographic features, arbitrary astronomical objects are unlikely to be visited or run across by a general reader of Wikipedia. Therefore, unless an astronomical object has significant coverage in the media or published sources, the likelihood that a general reader would choose to search Wikipedia for an arbitrary astronomical object is quite low. This is not a matter of dubious predictions; it is just common sense. Therefore, unlike Earth-based geographic features, the existence of an astronomical object, or even the fact that it has been named (see below) does not guarantee notability.

No inherited notability[edit]

In the sense that an object has been discovered or observed, it may have been noted by a scientist or scientists. For the purposes of this guideline, notable means having attracted significant notice in the spirit of WP:GNG. No astronomical object is exempt from this requirement, no matter what kind of object it is. If the individual object has received no or very little notice from independent sources, then it is not notable even though astronomical objects of its type are commonly notable. Also, just because the object is listed by name in a paper does not ensure notability. An object may be on the observation list of a large-scale survey, or a study of many objects of a specific type. Unless the astronomical object is the primary, or one of the primary, targets of a study, then such a study should not be used to support the object's notability.

Likewise, just because an object is listed in a database does not mean it is notable. Some databases and surveys, such as the JPL Small-Body Database or the Sloan Digital Sky Survey list hundreds of thousands or millions of objects (respectively). Other databases concern themselves with specific classes of objects and have fewer entries. Several, if not most, of the listed objects have little information beyond their physical parameters and discovery circumstances. It is not the job of Wikipedia to needlessly duplicate content in these databases. Likewise, just because, for example, a minor planet has been named by the Committee for Small-Body Nomenclature, this does not necessarily mean that object is notable. Unless the object has been the subject of significant commentary or significant study (i.e. beyond discovery and initial parameter constraints), it probably does not warrant an article.

This guideline does not prohibit the creation or maintenance of list articles that contain tables of properties and information related to astronomical objects. However, such lists are still subject to Wikipedia's content policies, such as verifiability and no original research.


If an astronomical object meets any of the following criteria, supported through independent reliable sources, it probably qualifies for a stand-alone article. If an astronomical object meets none of these criteria, it may still be notable, provided it meets the conditions of WP:NOTABILITY, though the merits of an article about an astronomical object will rest primarily on material that is verifiable through independent sources.

  1. The object is, or has been, visible to the naked eye. For ordinary stars, this includes any object with an HR catalogue identifier.
  2. The object is listed in catalogues of interest to amateur astronomers (e.g. Messier catalogue, Caldwell catalogue), or a catalogue of high historical importance (e.g. New General Catalogue). Being listed in comprehensive databases and surveys such as 2MASS or 2dFGRS isn't enough for notability.
  3. The object has been the subject of multiple, non-trivial published works. This includes published works in all forms, such as newspaper articles, books, television documentaries and articles in peer-reviewed scientific journals. A single paper is not enough to establish notability for most objects. Being mentioned alongside other similar objects, such as in a table of properties of 200 newly discovered supernovae, does not constitute non-trivial coverage; the paper needs to have significant commentary on the object.
  4. The object was discovered before 1850, prior to the advent of stellar astrophotography or automated technology. (The first asteroid discovered photographically was 323 Brucia in 1891.)

For the purposes of this guideline, "independent" means independent of the scientist or scientists who discovered the object, or others who may have a conflict of interest in promoting the object. The guideline does not prohibit the use of sources generated by the primary researchers, but they are not sufficient to establish notability.

Although some objects might qualify for a standalone article based on this guideline alone, it may still be best to create redirects to a more general article. For example, it might be best to consolidate the information about the individual planets of a planetary system on the article about its parent star. Whether it is best to consolidate or to have individual articles should be determined on a case-by-case basis, on the relevant article's talk page.

Note 1: These criteria do not supersede WP:NOTABILITY, they merely supplement and clarify it within the context of astronomical objects. If an astronomical object does not meet the general notability guideline, especially if it lacks evidence of significant coverage in independent, reliable sources, then it risks being merged or redirected to an existing article, or deleted altogether.

Note 2: Per WP:MASSCREATION, the systematic creation of articles on astronomical objects based on information retrieved from various astronomical databases should be discussed at WT:ASTRO first.

Note 3: Hypothesized or candidate astronomical objects may be notable if they have been subject to multiple, independent reliable sources that attest to their notability. Owing to WP:CBALL, it is irresponsible for Wikipedia to promote a hypothesized or candidate object as actually existing before confirmation by reliable sources. As with criterion 2 above, the mere fact that an astronomical object has been hypothesized to exist or has been included in comprehensive source catalogs of candidate objects is not enough to confer notability.

Failing all criteria[edit]

If no criteria can be met for either a standalone article or inclusion in a more general article, and attempts at improvements have not worked or cannot be reasonably tried, then there are two deletion procedures to be considered:[a]

  • For articles that do not meet the criteria for speedy deletion (WP:CSD#A7 especially), but are uncontroversial deletion candidates, place {{subst:PROD|concern=REASON TO DELETE}} at the top of the article. This allows the article to be deleted after 7 days if nobody objects (see Wikipedia:Proposed deletion, or PROD).
  • For cases where you are unsure about deletion or believe others might object, nominate the article for the Articles for deletion process (or AfD), where its merits will be discussed for 7 days.

When nominating an article for deletion (via either PROD or AfD process), please place {{WikiProject Astronomy|object=yes}} at the top of its talk page, as well as any other relevant Wikiproject templates (e.g. {{WikiProject Physics}} for an object which is of particular interest to physics). This will notify WikiProject Astronomy via WP:AALERTS that the article is being considered for deletion. If using the AfD process, you can also tag the deletion discussion with {{subst:delsort|Astronomy|~~~~}}, which will list the discussion at Wikipedia:WikiProject Deletion sorting/Astronomy.

Special cases[edit]

Failing basic criteria but possibly helpful in another article or list[edit]

If neither a satisfying explanation nor appropriate sources can be found for a standalone article, but a few sentences about the object may help another article or list:

  • If an appropriate list already exists (e.g. a sub-list of List of minor planets), then create a redirect for the object to the list. (For minor planets, see dealing with minor planets below.)
  • Be sure to Merge any appropriate information from the article into a broader article or list providing context.
  • If a basic redirect is not possible, but an article exists that the information could be merged, place a {{merge to}} tag on the page, indicating the page where the article may be merged. Be sure to start a section in the target article's talk page to discuss the merge.
  • If no article or list currently exists into which the astronomical object can be merged, consider writing the article yourself or request the article be written.

Astronomical objects that are part of a hierarchy of objects, such as a natural satellite system, planetary system or a star system, may be beneficially merged into the article about the system or hosting object. The criteria applied to merged article content are not the same as those applied to article creation. Content coverage within such system articles is governed by the principle of due weight and other content policies.

Only use AfD as a last resort for individual articles. If an editor is dealing with a large mass of articles, then redirect or PROD is more appropriate, because it is not ideal to flood AfD logs with these requests. When in doubt, bring the issue to WikiProject Astronomical objects for discussion.

Failure to explain the subject's notability[edit]

If an article does not explain the notability of its subject,[b] try to improve it by:

Insufficient sources[edit]

If an article fails to cite sufficient sources:

  • Look for sources yourself.
    • A good place to look for astronomical papers is the Astrophysics Data System (ADS) abstract service. Put the name of the object(s) in quotes and place it in the subject/keyword box. Try possible variations of the object's name if your first searches don't find any papers.
    • Many astronomical objects outside of the Solar System have an entry in the SIMBAD database. Try a lookup of the object by identifier, then use the "display -> reference summary" in the "reference" section. These will often have a link back to ADS, which may include free copies of the articles.
    • The NASA/IPAC Extragalactic Database (NED) contains data for over a million objects, including entries in the New General Catalogue (NGC). For each object, the data entries typically list the reference source as a bibliographic code that links back to an ADS abstract.
    • When using a search engine to look for information on an object, also try passing standard abbreviations or alternate catalogue identifiers as search terms. (See astronomical naming conventions.)
  • Ask for advice on where to look for sources on the article's talk page or at Wikipedia talk:WikiProject Astronomy.
  • Put the {{notability}} tag on the article to notify other editors.


Extrasolar planets[edit]

HAT-P-40 b is a hot jupiter exoplanet. Its discovery was announced in 2012 by the HATNet Project in a paper on three new discoveries. It has been included in several large catalogues and databases, and included in a list of possible targets for follow-up (where it was given the lowest priority). However, beyond the initial discovery paper, none of those sources provide any significant commentary on this particular exoplanet. There have been no observations by other teams of astronomers, nor has there been any coverage in the popular media. The object exists, but does not meet any of the criteria above so does not have an article on Wikipedia; instead it has a one-line entry in the List of exoplanets discovered in 2012. The host star (TYC 3607-1028-1) is not independently notable either, so also doesn't have an article.

Gliese 1214 b was discovered in 2009 by the MEarth Project; it was one of the first known super Earth exoplanets. There have been numerous studies by other teams of astronomers devoted to just this object, several of which have been reported in the popular media. It easily passes point 3 of the criteria, so rightly has a Wikipedia article.

Dealing with minor planets[edit]

Asteroid 182016 (1999 XF255) can be found on the JPL Small-Body Database (JPL SBDB). However, it does not show up in searches for additional references. The asteroid exists, but up to now is not an object that has warranted further study. Placing information about this object onto the corresponding list of minor planets page is more appropriate in this circumstance than creating a stand-alone article.

532 Herculina is another asteroid. This object has had many follow-up studies, including an observation by the Hubble Space Telescope. It is appropriate for an object like this to have a stand-alone article.

Before 2012, when this notability guideline did not yet exist, approximately 20,000 asteroid stubs were mass-created by bots and human editors. This created a considerable backlog of articles to be cleaned up, redirected, merged, or deleted. By consensus, asteroids numbered below 2000 should be discussed before re-directing. To not overly burden the community, editors should not nominate more than 10 asteroids a day to AfD for discussion. For asteroids numbered above 2000, if an article of questionable notability is found, and a good-faith search has failed to locate references establishing notability, then it is appropriate to redirect the stub to the appropriate list of minor planets article, keeping the original categories and {{DEFAULTSORT}} information. For best results, the redirect can be linked to the section containing the specific entry on the list article. For example, suppose you want to create a redirect to the section with the minor planet 57658 Nilrem entry on the List of minor planets: 57001–58000 article. This minor planet is found at the anchor #658 on the list page. Hence, a redirect can be created (see diff) with the following content:

#REDIRECT [[List of minor planets:57001–58000#658]]

{{NASTRO comment}}

[[Category:Main-belt asteroids|057658]]
[[Category:Discoveries by Michel Ory]]
[[Category:Astronomical objects discovered in 2001|20011017]]
[[Category:Minor planet redirects|57658 Nilrem]]

Objects named after famous individuals or characters[edit]

If an otherwise non-notable object has been named for a famous individual or mythological character, then it may be appropriate to include this information in the article for the individual or character (i.e. the notability of the asteroid is not inherited from its notable namesake). If the object is notable for other reasons, then of course the information may also be included in its article.

See also[edit]


  1. ^ Wikipedia editors have been known to reject nominations for deletion that have been inadequately researched. Research should include attempts to find sources that might demonstrate notability, and/or information that would demonstrate notability in another manner. See WP:BEFORE.
  2. ^ The text of an article should include enough information to explain why the object is notable. External arguments via a talk page or AFD debate page are not part of the article itself, and promises on those pages to provide information are not as valid as the existence of the information on the article page itself.