Take the following examples of star names/identifications:-

Regulus is the common name for a star.

HIP49669 is the Hipparcos ID for the star

HD87901 is the Henry Daper ID for the star

32 Leonis is the Flamsteed ID for the star

Alpha Leonis is the Bayer ID for the star

And now for a probably unrelated stars at random.

Why and how does stars like 'CW Tauri', 'DZ Bootis', 'IQ Lupi', 'EU Eridani' get their name, is there a catalogue for them? Who assigns their name? Do they individually mean something or randomly chosen letters? I'm not just after those stars but all stars with similar style naming.

Thanks in advance


3 Answers 3


The Bayer catalogue uses Greek letters, then lower case Latin letters and if needed, upper case letters. But it never gets beyond "Q"

In 1855, the German astronomer Argelander proposed naming a particular variable star "R" (as using upper case letters at the end of the alphabet would avoid clashing with the Bayer catalogue.

In 1867 it was agreed by the German astronomical society to name variable stars R,S,T... Z, then RR, RS, RT up to ZZ, followed by the constellation name.

This system provided enough names until 1907, when they reached ZZ Cygni. It was decided to start again with AA, up to AZ, Then BB to BZ etc. That system provides 344 names and worked only until 1929, and after that, when more variables than this were found in a single constellation, they switched to a 'Vxyz " where "xyz" is a number starting with 345 e.g. V345 Cyg.

So the "2-letter designation" is particular to variable stars http://cdsarc.u-strasbg.fr/afoev/var/edenom.htx and is used in the General Catalogue of Variable stars, but the scheme doesn't originate in the at Catalogue.

  • $\begingroup$ The scheme as you've outlined it of "2 letters + constellation" and as used most prominently by the General Catalog of Variable Stars, allows for 334 variables GCVS name list. when more variables than this were found in a single constellation, they switched to a 'Vxyz <constellation>" where "xyz" is a number starting with 345 e.g. V345 Cyg $\endgroup$ Commented May 15, 2020 at 22:47

Entering CW Tauri into Simbad's Identifier Query


returns this


Which leads to


That's one down. Please let us know what else you find.

  • $\begingroup$ So essentially, all those stars plus all the other stars with the same format name are listed in (General Catalog of Variable) then. I tested others other as well, seemed to be the same. $\endgroup$ Commented May 15, 2020 at 19:51

There is a distinction between a star name and a star designation.

Star names are a sub category of star designations.

Regulus is a star name, but the other identites of Regulus are more like star designations.

A star is usually referred to by its designation in some star catalog. Thus the star will be identified by giving its catalog name or abbreviation, and then by its number in the catalog.

Wikipedia's list of nearest stars and brown dwarfs shows the vast variety of star catalog designations.

The nearest star system is Alpha Centauri (Bayer designation).

Then Bernard's Star, also identified as (BD+04°3561a) from the Bonner Durchmusterung of 1859-1862.

Then Luhmann 16, a brown dwarf system discovered by Kevin Luhman.

Then WISE 0855-0714, another brown dwarf.

Then Wolf 359, number 359 in the Wolf catalog, also known as CN Leonis,it's variable star designation.

Then Lalande 21185, also known as BD+36°2147.

Then Sirius, Luyten 726-8, Ross 154, Ross 248, Epsilon Eridani, Lacaille 9362, Ross 128, EZ Aquarii, and so on and so on. There is Struve 3928, Groombridge 34, GJ 1961, Kruger 60, etc. as examples of various catalog designations.


There is a catalog of all know stars within a distance of 25 parsecs or 81.54 light years of the Sun, the Gliese Catalog of Nearby Stars, so all of the above stars also have Gliese catalog designations in addition to the the ones given in the Wikipedia list and in still other star catalogs.

The brighter a star appears as seen from Earth, the more names it will have in various Earth languages and cultures.

Star Names: Their lore and Meaning Richard Hinckley Allen, 1899, gives the names of many stars in various cultures.

Chinese star and constellation names are found in Stars of Jade: Astronomy & Star Lore of Ancient China.

This article lists some of the more important star catalogs.



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