How Did Stars Get Their Names?

The constellation Orion and the red supergiant Betelgeuse.
The constellation Orion holds the red supergiant star Betelgeuse (the red star in the upper left part of the constellation. Each star in this image has an official name, whether one like Betelgeuse or a number designation. Rogelio Bernal Andreo, CC By-SA.30

The brightest stars in the sky have names that date back thousands of years to a time when naked-eye observing was the state of the art in astronomy. So, for example, if you're looking at the constellation Orion, the bright star Betelgeuse (in his shoulder) has a name that opens up a window into the very distant past, when Arabic names were assigned to the very brightest stars. The same with Altair and Aldebaran and many, many others. They reflect the cultures and sometimes even the legends of the Middle Eastern, Greek, and Roman people who named them.

It has only been in recent times, as telescopes revealed more and more stars, that scientists began systematically assigning catalog names to stars. Betelgeuse is also known as alpha Orionis, and often shows up on maps as α Orionis, using the Latin genitive for "Orion" and the Greek letter α (for "alpha") to indicate it is the brightest star in that constellation. It also has the catalog number HR 2061 (from the Yale Bright Star Catalog), SAO 113271 (from the Smithsonian Astrophysical Observatory survey), and is part of several other catalogs. More stars have these catalog numbers than actually have any other type of names, and the catalogs help astronomers "bookkeep" the many different stars in the sky. 

It's All Greek to Me

For most stars, their names come from a mix of Latin, Greek and Arabic terms. Many have more than one name or designation. Here's how it all came about. 

About 1,900 years ago the Egyptian astronomer Claudius Ptolemy (who was born under, and lived during, the Roman rule of Egypt) wrote the Almagest. This work was a Greek text that recorded the names of stars as they had been named by various cultures (most were recorded in Greek, but others in Latin as per their origin).

This text was translated into Arabic and used by its scientific community. At the time, the Arab world was known for keen astronomical charting and documentation, and in the centuries after the fall of the Roman Empire, became the central repository of astronomical and mathematical knowledge. So it was their translation that became popular among astronomers.

The names for stars that we are familiar with today (sometimes known as traditional, popular or common names) are the phonetic translations of their Arabic names into English. For example, Betelgeuse, mentioned above, began as Yad al-Jauzā', which translates roughly to "the hand  [or shoulder] of Orion." However, some stars, like Sirius, are still known by their Latin, or in this case, Greek, names. Typically these familiar names are appended to the brightest stars in the sky.

Naming Stars Today

The art of giving stars proper names has ceased, largely because all the bright stars have names, and there are millions of dimmer ones. It would be confusing and difficult to name every star. So today, stars are simply given a numerical descriptor to signify their position in the night sky, associated with particular star catalogs. The listings are based on surveys of the sky and tend to group stars together by some particular property, or by the instrument that made the initial discovery of radiation, all the forms of light from that star in a particular waveband.

While not as pleasing to the ear, today's star-naming conventions are useful as researchers are studying a particular type of star in a specific region of the sky. All astronomers around the world agree to use the same numerical descriptions so as to avoid the kind of confusion that could arise if one group named a star a certain name and another group named it something else. 

Star Naming Companies

The International Astronomical Union (IAU) is charged with bookkeeping nomenclature for stars and other celestial objects. Official names are "okayed" by this group based on guidelines developed by the astronomical community. Any other names not approved by the IAU are not official names.

When a star is designated a proper name by the IAU, its members will usually assign it the name used for that object by ancient cultures if one is known to exist. Failing that, significant historical figures in astronomy are usually chosen to be honored. However, this is rarely the case either anymore, as catalog designations are a more scientific and easily used way to identify stars in research.

There are a few companies that purport to name stars for a fee. Chances are that you have heard of this practice, or even participated yourself. You pay a small fee and you can have a star named after you or someone you love. While nice, the problem is that these names are not actually recognized by any astronomical body. So unfortunately if something interesting is ever discovered about the star someone paid a fake company to name, that unauthorized name isn't going to be used. It's essentially a novelty that has no real value to astronomers. 

If you really want to name a star, how about going to your local planetarium and naming a star on its dome? Some facilities do this or sell bricks in their walls or seats in their theaters. Your donation goes for a good educational cause and helps the planetarium do its job of teaching astronomy. It's far more satisfying than simply paying a questionable company that claims "official" status for a name that won't ever be used by astronomers.

Edited and updated by Carolyn Collins Petersen