• MPC Preparation (Info)

  • How Are Minor Planets Named?

    The quick version: the discoverer of a particular object has the privilege of suggesting a name to a committee that judges its suitability. Contrary to some recent media reports it is not possible to buy a minor planet. If you have a name you would like to apply, the best advice is "Go out and discover one!". Information on how this might be achieved is available.


    A fuller description of how minor planets are named is given below, but you will need to understand some basic astronomical concepts in order to fully appreciate it.

    1. The assignment of a particular name to a particular minor planet is the end of a long process that can take many decades.

    2. It begins with the discovery of a minor planet that cannot be identified with any already-known multiple-opposition or recent single-opposition object. The observations are reported to the Minor Planet Center and the object stays on the NEO Confirmation Page until we have enough observations to compute a reliable orbit. Then a new provisional designation is assigned to the object. More information on how and when we remove objects from the NEO Confirmation Page can be found on the page containing Notes about the NEO Confirmation Page.

      • It is also possible to search for identifications with known objects. If an identification is made, one of the provisional designations is chosen by the identifier as the principal designation. The selection of which designation is chosen has no effect on who will be the discoverer when the object is numbered.

      • If no identifications are forthcoming, further observations of the new object are obtained and an orbit is computed. The object is followed for as long as possible at the discovery opposition (some objects are followed for three or four months). Additional searches for identifications can be made as each new set of observations is obtained. If any identifications are made one of the designations involved is chosen as the principal designation.

      • If no identifications are found and the observed arc reaches two or three months, it is likely that the object may be found as a result of a direct search at the next opposition.

    3. Further observations are made of the object at later oppositions. When there are observations at four or more oppositions the object may receive a permanent designation, a number. (The actual circumstances under which objects are numbered are rather complex and subject to occasional revision, but four well-observed oppositions will usually suffice.) For unusual objects, such as NEAs (Near-Earth Asteroids), numbering might occur after three, maybe even only two, oppositions.
      • The discoverer of the numbered object is defined in one of two ways:
        • For objects that had multiple-opposition orbits prior to the issuance of MPEC 2010-U20, the discover of the numbered object is the same as the discoverer of the principal designation.
        • For objects that became multi-opposition after that MPEC, the discoverer of the numbered object is the observer who made the earliest-reported observation at the opposition with the earliest-reported second-night observation.

      • This discoverer is accorded the privilege of suggesting a name for his/her discovery. The discoverer has the privilege for a period of ten years following the numbering of the object.

      • The discoverer writes a short citation explaining the reasons for assigning the name.

      • Discoverers have to submit name proposals and citations via a web-form: https://www.minorplanetcenter.net/submit_name. Registration is required to use this form and is only available to discoverers of numbered minor planets: send a request to contact@wgsbn-iau.org, noting which objects (discovery site or discoverer name, not individual objects) you wish to have access to.

    4. Names and citations proposed by discoverers are judged by the Working Group Small Body Nomenclature (WGSBN) of the International Astronomical Union. The WGSBN has published the rules and guidelines relating to the naming of minor planets, as well as the special naming rules for objects in certain orbital classes. The document also includes information on the procedures used to accept or reject proposals.

    5. Names become official when they appear in the WGSBN Bulletin, published by the WGSBN.


    An alphabetical list of minor-planet names is available.