Wikipedia:Notability (astronomical objects)

This guideline reflects established consensus about the notability of astronomical objects, which is required for them to be the topic of a Wikipedia article. It is a subject-specific supplement to the general notability guideline, developed by Wikiproject Astronomy.

Scope
This guideline applies to astronomical objects – naturally occurring physical bodies, associations, or structures that exist in outer space. This includes galaxies, nebulae, star clusters, star systems, individual stars, planets, minor planets, asteroids, comets, and moons. It also includes bodies of matter that are held together by masses other than their own, such as circumstellar discs, accretion discs, or zodiacal dust; regions defined by the large-scale structure of the Universe (e.g. galaxy filaments and cosmic voids); and groups that appear solely due to Earth's viewing perspective (e.g. asterisms and optical double stars).

It does not cover artificial objects in space (such as artificial satellites or spacecraft); the airspace of Earth; extraterrestrial geologic features (such as craters or mountains); or extraterrestrial material that has been transported to Earth (such as Moon rocks, meteor showers and meteorites). Nor does this guideline apply to fictional objects, such as those that appear in science fiction. Candidate objects or those which are the subject of serious scientific hypothesis are discussed below.

Establishing notability
On Wikipedia, 'notable' means 'worthy of notice'; it is not synonymous with 'famous' or 'important'. Astronomical objects are notable if they have received substantial attention and coverage in reliable sources, usually the scientific literature and/or popular media. Famous astronomical objects have readily available verifiable information from reliable sources that indicate notability; however, more obscure objects can still be notable.

Coverage must be specific and substantial: notability is not ensured just because an object is listed in a scientific paper or included in a large-scale astronomical survey. To establish notability, the astronomical object must have significant commentary in reliable sources, such as being one of the primary targets of a study with in-depth discussion (beyond discovery and basic parameters).

Being listed in a database does not make an object notable. Some astronomical databases and surveys, such as the JPL Small-Body Database, SIMBAD or the Gaia catalogue, list millions or billions of objects. Many objects listed in catalogues and databases have little information beyond their basic parameters and discovery circumstances. Wikipedia does not duplicate content in these databases.

No inherent notability
Notability is determined solely by coverage in reliable sources, not whether editors personally believe an astronomical object is important. Just because an astronomical object exists in space does not mean it is necessarily notable i.e. there is no inherent notability without coverage in reliable sources.

On Earth, many named places are considered notable, but this is not true for astronomical objects: the naming of a body in space (such as an asteroid) does not confer notability. It is much less likely that there are sufficient sources to write a Wikipedia article for an arbitrary astronomical object than an arbitrary place on Earth. For example, if a minor planet has received an official name from the Committee for Small Body Nomenclature, that does not necessarily mean that object is notable. If an astronomical object has been named but is not notable, it could still be included in a suitable list of similar objects.

No inherited notability
For the purposes of establishing notability, coverage must be of the astronomical object itself, not other things that may be related to it. Merely being associated with another notable topic does not mean the object itself is notable, i.e. there is no inherited notability.

For example, if an object was discovered by a famous astronomer, that does not necessarily make it notable. Nor does being named after something notable make the object itself notable. If the individual object has received insufficient coverage in independent sources, then it is not notable even if similar objects are often notable. Moons of a notable planet are not necessarily notable, and planets of a notable star are not necessarily notable.

Criteria
If an astronomical object meets any of the following criteria, it is presumed notable. These criteria below are presented as rules of thumb for easily identifying astronomical objects that Wikipedia should probably have articles about. In almost all cases, a thorough search for independent, third-party reliable sources will be successful for an astronomical objects meeting one or more of these criteria. However, meeting these criteria is not an absolute guarantee that Wikipedia should have a separate, stand-alone article entirely dedicated to the astronomical object.


 * 1)  The object is, or has been, visible to the naked eye. This includes any star in the HR catalogue.
 * 2)  The object is listed in a catalogue of high historical importance (e.g. Messier catalogue), or a catalogue of high interest to amateur astronomers (e.g. Caldwell catalogue).
 * 3) * Being listed in comprehensive databases (e.g. SIMBAD or NED) or surveys (e.g. 2MASS or 2dFGRS) isn't enough for notability.
 * 4)  The object has been the subject of multiple non-trivial published works, which contain significant commentary on the object. This includes published works in all forms, such as newspaper articles, books, television documentaries and articles in peer-reviewed scientific journals.
 * 5) * A single paper is not enough to establish notability. Being mentioned alongside other similar objects, such as in a table of properties of 200 newly discovered supernovae, does not constitute non-trivial coverage.
 * 6)  The object was discovered before 1850, prior to the use of astrophotography or automated technology.

Whether an object meets these criteria must be established through independent reliable sources, following WP:NRV. This means independent of the scientist(s) who discovered the object, or others who may have a conflict of interest in promoting it. Sources generated by the discoverers may be used as references for factual information in the article, but they cannot be used to establish notability. See guidance below on finding sources.

Notable for other reasons
If an astronomical object meets none of these criteria, it could still be notable for other non-astronomical reasons e.g. as a literary topic. Such cases should follow the general notability guideline.

Inclusion in another article or list
If an astronomical object is not notable, so cannot have its own article, a few sentences about the object might be useful in another article or it could be included in a list.


 * Appropriate information can be merged into a broader article. Mergers should be proposed and discussed to establish consensus before being implemented. Place a merge to tag on the page, indicating the page where the article may be merged, and start a section in the target article's talk page to discuss the proposed merge.
 * If the information is more appropriate to being incorporated into an existing list (see lists of astronomical objects), then a) ensure there is an entry for the object included in the list, adding one if necessary; and b) create a redirect from the name of the object to the list. (For minor planets, see dealing with minor planets below.)
 * If no article or list currently exists into which the astronomical object can be incorporated, consider writing one yourself or submit a request for it. Such lists are still subject to Wikipedia's content policies, such as verifiability and no original research.

Astronomical objects that are part of a hierarchy of objects, such as a planetary system or star system, can often be beneficially merged into the article about the wider system or hosting object. For example, if there are several exoplanets orbiting a single star, they could be discussed in a section of the article on the host star, rather than each planet having a separate article. Content included in a broader article is not subject to the same notability criteria as stand-alone articles; instead it is governed by the principles of due weight and the general content policies.

Deletion
If none of the criteria are met, the object isn't notable for other reasons, and there is no suitable target for a merger, deletion may be necessary. See the deletion policy for further steps.

When nominating an article for deletion (via either the PROD or AfD process), please place  at the top of its talk page, as well as any other relevant Wikiproject templates (e.g.   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, which will list the discussion at WikiProject Deletion sorting/Astronomy.

Finding sources
Many astronomical objects have more than one valid name or catalogue designation, see astronomical naming conventions. When searching for sources, try using alternative identifiers or standard abbreviations e.g. 'kap Cep' or 'HR 7750' for Kappa Cephei, or 'NGC 2392' for the Eskimo Nebula.

There are several astronomy-specific search engines which can be consulted:
 * The Astrophysics Data System (ADS) abstract service lists almost all published papers and preprints in astronomy, and many conference proceedings and textbooks too. Links are provided to the published source and any freely-available version (such as a preprint or scanned version of older sources). Put the name of the object(s) in quotes and place it in the 'abstract/keyword' box.
 * The SIMBAD database provides information on millions of astronomical objects outside the Solar System, including basic properties, alternative designations, and a bibliography. Coverage is best for objects within the Milky Way, with less complete coverage of extragalactic sources. Try a search by identifier, or by coordinates, then click 'display' in the 'references' section. Clicking on any of the entries will provide links to the published paper and/or the relevant ADS entry.
 * The NASA/IPAC Extragalactic Database (NED) contains information on extragalactic objects, for which it is more comprehensive than SIMBAD. Try a search by identifier, or by coordinates, then click on the 'references' tab. You can then either click the 'view references on ADS' button, or click on a specific reference and then 'search ADS' to go to the ADS record.

There is no equivalent to SIMBAD or NED for objects within the Solar System.

Mass creation
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.

Hypothetical objects
Candidate astronomical objects, or those proposed by a serious scientific hypothesis, are notable only if they have received substantial commentary in multiple independent reliable sources, per criterion 3. Any article about the object must explicitly state that it is hypothetical or a candidate, unless/until confirmed by multiple independent reliable sources. Care should be taken with popular media sources based upon a press release issued by the discoverer or proposer, as they might not be independent (see churnalism). Substantial original journalism and/or comments from independent experts are necessary to establish the notability of hypothetical or candidate objects.

Dealing with minor planets
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. To not overly burden the community, editors should not nominate more than 10 asteroids a day to AfD for discussion.

By consensus, asteroids numbered below 2000 should be discussed before re-directing. 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 article to the corresponding list of minor planets, keeping the original categories and information. For best results, the redirect should use NASTRO comment and target the specific entry on the list article.

For example, suppose you want to create a redirect to the minor-planet entry  on the List of minor planets: 57001–58000 article. This minor planet is found at the anchor  on the list page. Hence, a redirect can be created with the following content:

The template Anchor can be used to create a stable anchor point for a redirect.

Extrasolar planets
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). In 2019, it was assigned the proper name 'Vytis' by NameExoWorlds. However,, none of those sources provide any significant commentary on this particular exoplanet beyond the initial discovery paper. 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 the third criterion, so is notable and has a stand-alone article.

Minor planets
The asteroid is listed in the JPL Small-Body Database and by the Minor Planet Center. However, it does not appear in searches for additional references. The asteroid exists, but has received no substantial commentary, or study beyond refining its orbit. Information about this object is therefore included in the corresponding list of minor planets, not a stand-alone article.

532 Herculina is another asteroid. It has received multiple follow-up studies, by teams of astronomers unrelated to the discoverer, including an observation by the Hubble Space Telescope. Independent references provide substantial commentary on its shape and discussion of a possible asteroid moon. It is therefore notable and has a stand-alone article.

Objects named after famous individuals or characters
The notability of astronomical objects is not inherited from any famous individual or mythological character they may be named after. If a non-notable asteroid is named after a notable person or character, it may be appropriate to include this information in the article about the person or character.

For example, the asteroid 165347 Philplait was named after Phil Plait, a notable astronomer, but the asteroid does not meet the criteria above. Instead, 165347 Philplait redirects to and the naming of the asteroid is mentioned at. The asteroid is in the list article meanings of minor planet names.

If an object is notable under the criteria above, then the origin of its name should be explained in its article. An example is 45 Eugenia, which is named after the Empress Eugénie de Montijo but is notable for other reasons.