Designations of stars (and other celestial bodies) is currently mediated in the scientific community by the International Astronomical Union (IAU). Many of the star names in use today were inherited from the time before the IAU existed. Other names, mainly for variable stars (including novae and supernovae), are being added all the time.

Approximately 10,000 stars are visible to the naked eye.[1] Pre-modern catalogues listed only the brightest of these. Hipparchus in the 2nd century BC enumerated about 850 stars. Johann Bayer in 1603 listed about twice this number. Only a minority of these have proper names; all others are designated by numbers from various catalogues. Only in the 19th century did star catalogues list the naked-eye stars exhaustively. The most voluminous modern catalogues list on the order of a billion stars, out of an estimated total of 200 to 400 billion in the Milky Way.

Proper names

Main article: List of proper names of stars

In 2016, the IAU organized a Working Group on Star Names (WGSN)[2] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[3] included a table of the first two batches of names approved by the WGSN (on 30 June and 20 July 2016) together with names of stars adopted by the IAU Executive Committee Working Group on Public Naming of Planets and Planetary Satellites during the 2015 NameExoWorlds campaign[4] and recognized by the WGSN. These names are incorporated in the IAU Catalog of Star Names.[5]

Several hundred of the brightest stars have traditional names, most of which derive from Arabic, but a few from Latin.[6] There are a number of problems with these names, however:

In practice, the traditional names are only universally used for the very brightest stars (Sirius, Arcturus, Vega, etc.) and for a small number of slightly less bright but "interesting" stars (Algol, Polaris, Mira, etc.). For other naked eye stars, the Bayer or Flamsteed designation is often preferred.

In addition to the traditional names, a small number of stars that are "interesting" can have modern English names. For instance Barnard's star has the highest known proper motion of any star and is thus notable even though it is far too faint to be seen with the naked eye. See stars named after people.

Two second-magnitude stars, Alpha Pavonis and Epsilon Carinae, were assigned the proper names Peacock and Avior respectively in 1937 by Her Majesty's Nautical Almanac Office during the creation of The Air Almanac, a navigational almanac for the Royal Air Force. Of the fifty-seven stars included in the new almanac, these two had no classical names. The RAF insisted that all of the stars must have names, so new names were invented for them.[7] These names have been approved by the IAU WGSN.[5]

The book Star Names: Their Lore and Meaning by R.H.Allen (1899)[8] has had effects on star names:

A few stars are named for individuals. These are mostly names in common use that were taken up by the by the scientific community at some juncture. The first such case (discounting characters from mythology) was Cor Caroli (α CVn), named in the 17th century for Charles I of England. The remaining examples are mostly named after astronomers, the best known are probably Kapteyn's Star and recently Tabby's Star.

Catalogue numbers

In the absence of any better means of designating a star, catalogue numbers are generally used. Many star catalogues are used for this purpose; see star catalogues.

By constellation

The first modern schemes for designating stars systematically labelled them within their constellation.

Full-sky catalogues

Full-sky star catalogues detach the star designation from the star's constellation and aim at enumerating all stars with apparent magnitude greater than a given cut-off value.

Variable designations

Main article: variable star designation

Variable stars that do not have Bayer designations are assigned designations in a variable star scheme that superficially extends the Bayer scheme with capital Latin letters in front of the constellation name, starting with letters R to Z. Such designations mark them as variable stars, examples are R Mira, RR Lyrae, etc. (Many variable stars also have designations in other catalogues.)

Exoplanet searches

When a planet is detected around a star, the star is often given a name and number based on the name of the telescope or survey mission that discovered it and based on how many planets have already been discovered by that mission e.g. HAT-P-9, WASP-1, COROT-1, Kepler-4.

Sale of star names by non-scientific entities

Star naming rights are not available for sale via the IAU. Rather, star names are selected on a non-commercial basis by a small number of international organizations of astronomers, scientists, and registration bodies, who assign names consisting usually of a Greek letter followed by the star's constellation name, or less frequently based on their ancient traditional name.[9]

However, there are a number of non-scientific "star-naming" companies that offer to assign personalized names to stars within their own private catalogs. These names are used only within that company (and usually available for viewing on their web site), and are not recognized by the astronomical community, or by competing star-naming companies.[10] A survey conducted by amateur astronomers discovered that 54% of consumers would still want to "name a star" with a non-scientific star-naming company even though they have been warned or informed such naming is not recognized by the astronomical community.[11] As far as risks associated with naming a star at a non-scientific star-naming company, the IAU says the activity will not make you ill and it is an exchange of money for a feeling of happiness.

See also


  1. ^ Under average conditions, about 5,600 stars brighter than magnitude +6 are visible to the naked eye; theoretically, under perfect conditions, about 45,000 stars brighter than magnitude +8 would be visible.[citation needed]
  2. ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
  3. ^ "Bulletin of the IAU Working Group on Star Names, No. 1" (PDF). Retrieved 28 July 2016.
  4. ^ "Final Results of NameExoWorlds Public Vote Released" (Press release). 15 December 2015.
  5. ^ a b "IAU Catalog of Star Names". Retrieved 28 July 2016.
  6. ^ The NASA in 1971 compiled a "technical memorandum" collecting a total of 537 named stars. Rhoads, J. W.,Technical Memorandum 33-507 – A Reduced Star Catalog Containing 537 Named Stars, NASA-CR-124573 (1971).
  7. ^ Sadler, Donald H. (2008). "A Personal History of H.M. Nautical Almanac Office" (PDF). United Kingdom Hydrographic Office. Retrieved 2010-09-26.
  8. ^ Richard Hinckley Allen (1963-06-01). Star Names: Their Lore and Meaning. Dover Publications. ISBN 978-0486210797.
  9. ^ Naming of Astronomical Objects
  10. ^ Andersen, Johannes. "Buying Stars and Star Names". International Astronomical Union. Retrieved 2013-06-04.
  11. ^ Haselden, Derek. "Naming and Buying Stars: What you should know". Solent Amateur Astronomers. Retrieved 2016-08-10.