The IAU frequently receives requests from individuals who want to buy stars or name stars after other persons. Some commercial enterprises purport to offer such services for a fee. However, such "names" have no formal or official validity whatsoever. Similar rules on "buying" names apply to star clusters and galaxies as well. For bodies in the Solar System , special procedures for assigning official names apply (see the IAU theme "Naming Astronomical Objects"), but in no case are commercial transactions involved.

Some bright stars have proper names, with mostly Arabic, Greek, or Latin etymologies (e.g. Vega), but otherwise the vast majority of stars have alphanumeric designations — consisting of an acronym plus either an index number or celestial position (e.g. HR 7001, 2MASS J18365633+3847012). The IAU supports a Working Group on Star Names (WGSN) under Division C which is cataloguing the names of stars from the world’s cultures, and maintaining a catalogue of approved unique proper names (e.g. Sirius, Proxima Centauri, etc.). After ongoing investigation of cultural star names from around the world, the WGSN may adopt “new” official IAU star names from this list for those stars currently lacking official IAU names. This will help preserve astronomical heritage while providing new unique names for the international astronomical community. Names for exoplanets and their host stars may be also approved by the IAU Executive Committee Working Group on the Public Naming of Planets and Planetary Satellites, as was done in 2015 via the NameExoWorlds contest.

As an international scientific organization, the IAU dissociates itself entirely from the commercial practice of "selling" fictitious star names, surface feature names, or real estate on other planets or moons in the Solar System. Accordingly, the IAU maintains no list of the (several competing) enterprises in these businesses in individual countries of the world. Readers wanting to contact such enterprises despite the explanations given below should search commercial directories in their country of origin.

In the past, certain such enterprises have suggested to customers that the IAU is somehow associated with, recognizes, approves, or even actively collaborates in their business. The IAU wishes to make it totally clear that any such claim is patently false and unfounded. The IAU would appreciate being informed, with appropriate documentation, of all cases of illegal abuse of its name, and will pursue all documented cases by all available means.

Thus, like true love and many other of the best things in human life, the beauty of the night sky is not for sale, but is free for all to enjoy. True, the 'gift' of a star may open someone's eyes to the beauty of the night sky. This is indeed a worthy goal, but it does not justify deceiving people into believing that real star names can be bought like any other commodity.

Nevertheless, the IAU continues to receive requests for naming stars regardless. You may contact iauinfos@iap.fr if you have more questions. Further informal/humorous explanations of some of the issues involved are offered in the section below.

Layman's Guide to Naming Stars

The following lists some frequently asked questions and simple, informal answers about naming stars and other celestial bodies (for more serious scientific explanations, see the theme Naming Astronomical Objects). For purposes of discussion of stellar nomenclature, astronomers usually refer to alphanumeric designations (e.g. HR 7001, HD 172167, Alpha Lyrae) and proper names (e.g. Vega). All stars have designations, often many, however very few stars have proper names - usually only ones of cultural, historical, or astrophysical interest.

Q: Who is the International Astronomical Union (IAU)? By what authority does the IAU name stars?

A: The International Astronomical Union (IAU) was founded in 1919. Its mission is to promote and safeguard the science of astronomy in all its aspects through international cooperation. Its individual members — structured in Divisions, Commissions, and Working groups — are professional astronomers from all over the world, at the Ph.D. level and beyond, and active in professional research and education in astronomy. The IAU has over 12,000 Individual Members from more than 90 countries worldwide. There are 79 National Members represented by national science academies and/or national astronomical organizations, and those nations comprise three-quarters of the Earth’s population.

Since its inception, one of the IAU’s activities has been to standardize nomenclature of celestial objects among the international astronomical community. Over the past century, various IAU working groups comprised of astronomers from around the world have standardized nomenclature for constellations, surface features on the Moon, planets, planetary satellites, and small bodies; planetary satellites, asteroids, and objects outside the Solar System. These efforts have stemmed from necessity as sometimes designations/names have been ambiguous or confusing.

The names approved by the IAU represent the consensus of professional astronomers around the world and national science academies, who as “Individual Members” and “National Members”, respectively, adhere to the guidelines of the International Astronomical Union. The IAU is organized into an Executive Committee, and several Divisions, Commissions, and Working Groups. Every three years, the IAU General Assembly votes for members of the Executive Committee which leads and organizes the Union’s activities. Most relevant to the issue of nomenclature, there are IAU Working Groups which carry out well-defined tasks on behalf of the IAU (these tasks are spelled out in Terms of Reference approved by IAU leadership).

Q: Why don't stars get real names instead of these boring numbers?

A: The reason to give a celestial object a designation or name is to facilitate locating, describing, and discussing it. Alphanumeric designations are usually sorted by position, which historically made them easy to look up in catalogues. Precise coordinates (positions in the sky), possibly found via a catalogue number, provide an exact identification. Names are fine for small groups of well-known objects, like the planets or naked-eye stars, but are simply not practicable for catalogues of millions of stars. Hundreds of stars have names for some cultural reasons (mythology, navigation, agricultural seasons, timekeeping, etc.) or scientific reasons (variability, proximity, unusual properties, exoplanet host star, etc.). The IAU has formally recognized a couple hundred proper names for stars via the Working Group on Star Names (WGSN) and some exoplanet host stars via the IAU Executive Committee Working Group on Public Naming of Planets and Planetary Satellites. The WGSN is also in the process of cataloguing names of stars from cultures around the world.. Some of these cultural names may eventually be approved as official IAU proper names for these stars. At this point, the focus of the WGSN’s activities is on names of stars of historical, cultural, or astrophysical importance.

Q: But wouldn't it be fun anyway?

A: Some people might be amused while the present fashion lasts, but it would generate a system of mounting confusion for no factual reason. And this is the opposite of what taxpayers pay scientists to do.

Q: Who is legally responsible for naming objects in the sky?

A: For nearly a century, the IAU has been the internationally recognized authority for naming celestial bodies and surface features on them. And names are not sold, but assigned according to internationally accepted rules.

Q: What does this mean in practice?

A: Simply this: Names assigned by the IAU are recognized and used by scientists, space agencies, authors of astronomical literature, and other authorities worldwide. When observing stars and planets or launching space missions to them, or reporting about them in the news, everybody needs to know exactly which location a particular name refers to. The names assigned by the IAU are those that are used. These rules are firm where claims of property could theoretically be made, i.e. primarily in the solar system (where also treaties negotiated through the United Nations apply). Terrestrial makers of international law have so far had more urgent concerns than creating rules for "buying" totally inaccessible corners of infinite space, so there is no written text that can be twisted and interpreted - just a plain and practical fact.

Q: But if I want to, can I buy the name of a star anyway?

A: Sure, there are people who will be more than happy to take your money....

Q: Can you tell me who and where?

A: Sorry, we are a scientific organization, not a branch of the entertainment industry. We cannot distribute addresses of enterprises selling fictitious goods.

Q: OK, I found a dealer myself; what will I get from them?

A: An expensive piece of paper and a temporary feeling of happiness, like if you take a cup of tea instead of the Doctor's recommended medicine. But at least you do not risk getting sick by paying for a star name, only losing money.

Q: But that name is unique, I understand?

A: It will be likely unique in that company's name list. Otherwise you can probably sue them. But there are more than enough stars for everybody who wants to buy the name of one. However, no countries, authorities, or scientists in the world will recognize "your" name for the star. Nothing prevents your or any other dealer from selling "your" star to anyone else.

Q: My friends tell me the name is preserved forever?

A: Sorry, also not: The name you paid for can be ignored, forgotten, or sold again to anyone else by anyone at any time.

Q: But the company says their name list is registered with the National Library - isn't that a guarantee for authenticity?

A: Sorry again: Anyone can (in fact usually must ) send a copy of any published book to the National Library. Giving the book a number doesn't mean that the Library approves the contents or checks that no companies "sell" the same star to different people.

Q: Surely the courts will recognize the name I have paid for?

A: Try to contact your lawyers. Chances are that they will either laugh their heads off or politely suggest that you could invest their fees more productively...

Q: But what about the companies that sell pieces of territory on the Moon and other planets? Those are within reach, we know, so surely I own the piece that I have bought?

A: See the answer to the previous question. As a minimum, we suggest that you defer payment until you can take possession of your property...

Q: The IAU pretends to be in charge of the sky - why don't you DO something about this??!

A: Sorry, much as we would like to, we are not under the illusion that the IAU can eradicate charlatanry: It has survived and thrived for countless centuries in many disguises - some far more dangerous than this particular example. All we can do is warn the public and try to prevent the abuse of our name and scientific reputation to mislead well-meaning customers.

Q: All this sounds negative and grouchy. I love the stars and a very special person and want to do something for him/her. What can I do ?

A: Lots! Go to your nearest planetarium or local amateur or professional observatory. They are staffed with people who feel just the same. They often have stores with books with wonderful astronomy pictures from the ground or from space, or fine astronomy magazines that all make great gifts. They can also direct you to the local astronomy club or society where enthusiasts will be happy to show you (and your friend!) the real stars through their own telescopes. Maybe you'll get infected and end up buying a telescope yourself?

Alternatively, if you do wish to have a personal star but prefer to stay inside, you can now also explore the entire sky in the comfort of your own home: Digital sky surveys are online (see for instance http://www.worldwidetelescope.org/). This allows you to browse through many hundreds of millions of stars on your home computer and print out a chart of any one that pleases you. These public digital maps are in fact the main database of at least some of the commercial star naming enterprises and cost about the same as the name of a single star. So why pay a markup for buying your stars one at a time? Enjoy!

Adapted from a text by former IAU General Secretary Johannes Andersen