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Traditional Names of Astronomical Objects

Most cultures have devised traditional names for astronomical objects, and many have established complex mythologies. These often relate to the naked-eye planets, the Milky Way and to constellation patterns.

In considering traditional Welsh names, we need to remember that Welsh culture has been integrated into broader European culture for millenia. Therefore, many Welsh-language names are the Welsh equivalents of the general European names. For example, the Welsh-language names of the planets are the Welsh names of the Roman gods after which the Romans named the planets: Mercher (Mercury), Gwener (Venus), Mawrth (Mars), Iau (Jupiter) and Sadwrn (Saturn), Uranws (Uranus), Neifion (Neptune) and Plwto (Pluto) (with, outside this pattern, Y Ddaear for the Earth). Standard Latin names (e.g. Orion) have generally been used for constellations, but some Welsh-language translations have also been used where appropriate (e.g. Yr Arth Fawr [The Great Bear] for Ursa Major, Yr Arth Fach [The Little Bear] for Ursa Minor, Y Llew [The Lion] for Leo). Similarly, star names used historically in Wales have been the standard international names (e.g. Sirius, Procyon, Rigel). It is interesting for us here to consider astronomical names of specifically Welsh origin.

An additional issue faces us when considering traditional names for star patterns and constellations. Iolo Morgannwg (Edward Williams; 1747-1826) produced a body of false scholarship at the end of the eighteenth century and the early nineteenth century, particularly in relation to claimed traditions derived from ancient Druidic sources. Some discussions of traditional Welsh star pattern names have used the work of John Williams ("Ab Ithel", 1811-1862), some of whose writing is based on genuine manuscripts and some on the fraudulent work of Iolo Morgannwg. Great caution is therefore needed to avoid using unreliable sources.

A careful search through literature can find some sources that are unlikely to have been contaminated by the fake scholarship of Iolo Morgannwg and his followers. One particularly useful source is the astronomical section, Arweiniad i Wybodaeth o Seryddiaeth ("A Guide to a Knowledge of Astronomy"), that Robert Roberts (1777-1836) of Holyhead placed at the start of his geographical book Daearyddiaeth ("Geography", published in Chester in 1816). Robert Roberts was well read in astronomy, and science more generally, and we can view him as a relatively reliable source. A few traditional astronomical names appear in old poetry, and therefore clearly predate the writings of Iolo Morgannwg.

This table is a compilation of traditional names from sources which are considered reliable.

Traditional name Direct translation
into English
Common modern Welsh name Description References
Caer Gwydion/
Caer Gwdion
Fort of Gwydion Milky Way Llwybr Llaethog Disc of the Galaxy [2,3]
Bwa'r Gwynt/
Heol Y Gwynt/
Llwybr Y Gwynt
Arch of the Wind/
Road of the Wind/
Path of the Wind
Milky Way Llwybr Llaethog Disc of the Galaxy [12]
Y Ffordd Wen The White Road Milky Way Llwybr Llaethog Disc of the Galaxy [12]
Llun Y Llong Image of the Ship The Plough Yr Aradr Asterism [4,5]
Y Llong Foel The Bare Ship The Plough Yr Aradr Asterism [6]
Saith Seren Y Gogledd The Seven Stars of the North The Plough Yr Aradr Asterism [4]
Y Sospan The Saucepan The Plough Yr Aradr Asterism [12]
Men Carl/
Men Charles
Charles's Wain/
Charles's Wagon
The Plough Yr Aradr Asterism [12]
Jac a'i Wagen Jack and his Wagon The Plough Yr Aradr Asterism [12] Mid Wales regional name
Yr Haeddel Fawr The Great Plough Handle The Plough Yr Aradr Asterism [4]
Yr Haeddel Fach The Little Plough Handle Ursa Minor Ursa Minor Constellation [4]
Caer Arianrod/
Caer Arianrhod
The Fort of Arianrod/
Fort of Arianrhod
Corona Borealis Corona Borealis Constellation [7]
Y Twr Tewdws The Thick Group Pleiades Pleiades Open cluster [8,11]
Y Saith Seren Siriol The Seven Cheerful Stars Pleiades Pleiades Open cluster [12]
Y Trypser Pleiades Pleiades Open cluster [12] South Wales regional term
Llathen Fair Mary's Yard Belt of Orion Gwregys Orion Three bright stars in a line [9,10]
Llathen Teiliwr The Tailor's Yard Belt of Orion Gwregys Orion Three bright stars in a line [12]
Y Tri Brenin The Three Kings Belt of Orion Gwregys Orion Three bright stars in a line [12]
Y Groes Fendigaid The Blessed Cross Belt of Orion Gwregys Orion Three bright stars in a line [12]
Telyn Arthur Arthur's Harp Lyra Lyra Constellation [6]
Llys Dôn The Court of Dôn Cassiopeia Cassiopeia Constellation [1,12]

Some of these, such as Caer Arianrod, Telyn Arthur and Llys Dôn, are named after characters in the Mabinogi folk tales.

The Plough, the famous asterism (i.e. a group of prominent stars, not properly a constellation) in the constellation of Ursa Major has a number of traditional names. Yr Aradr ("The Plough") is a direct translations of the name common in English-speaking countries. The Plough has also been called Yr Haeddel Fawr ("The Great Plough Handle") and Ursa Minor Yr Haeddel Fach ("The Little Plough Handle"), which are somewhat different to the English equivalent. Men Carl (Charles's Wain or Charles's Wagon) is the Welsh equivalent of a name found commonly across European cultures, derived from Charlemagne's Wain after the Frankish king and first Holy Roman Emperor. [13] Jac a'i Wagen, interestingly, also has an association with a cart.

There are, however, some names particular to Wales.

[1]   Robert Roberts, Daearyddiaeth, publ. Chester, 1816, page 68.
[2]   G. R. Isaac, Llen Cymru, vol. 25, no. 1, pp. 12-20, 2002, who quotes evidence from 1547 (William Salesbury's dictionary) and the 17th century (manuscript by John Jones, Gellilyfdy).
[3]   A. Breeze, Review of English Studies, vol. 45, no. 177, pp. 63-69, 1994, who quotes references in poetry from the 14th and 15th centuries, and in Salesbury's "A Dictionary in Englyshe and Welshe" of 1547.
[4]   Y Brython, vol. 1, no. 13, p. 203, 17 Sep 1858, which refers to Donati's Comet close to Llun y Llong, which is also called Saith Seren y Gogledd.
[5]   Y Gwyddoniadur Cymreig, ed. John Parry, publ. Thomas Gee, Denbigh, 1875, in the article "Arcturus". The article contains some factual errors, but the identification of Llun y Llong is sound.
[6]   Robert Roberts, Daearyddiaeth, publ. Chester, 1816, pages 15 and 72.
[7]   Robert Roberts, Daearyddiaeth, publ. Chester, 1816, page 69.
[8]   Robert Roberts, Daearyddiaeth, publ. Chester, 1816, pages 16 and 74.
[9]   Robert Roberts, Daearyddiaeth, publ. Chester, 1816, page 16.
[10]   Robert Parry, (Robyn Ddu Eryri), Teithiau a Barddoniaeth Robyn Ddu Eryri, publ. H. Huphreys, Caernarfon, 1857, page 80.
[11]   W. O. Pughe, A Dictionary of the Welsh Language Explained in English, volume 2, second edition, publ. Thomas Gee, Denbigh, 1832 (under the definition of "twr"), who quotes Dafydd ap Edmwnd ("Tair tid fal y twr tewdws", "Three chains like the Pleiades").
[12]   B. Griffiths & D. G. Jones, The Welsh Academy English-Welsh Dictionary, publ. University of Wales Press, Cardiff, 1995.
[13]   R. H. Allen, Star Names: Their Lore and Meaning, publ. Dover Publications, New York, 1963 (a reprint of Star-Names and Their Meanings, publ. G. E. Stechert, 1899).

Names of Astronomical Objects Approved by the International Astronomical Union

The International Astronomical Union is the body responsible for assigning formal names to astronomical objects. Historically names were taken from classical Latin and Greek mythology. As larger numbers of astronomical objects have been discovered and mapped, names have been taken from a much more diverse range of the world's cultures. For the record, names assoicated with Wales are mentioned here.

Lunar features

Some craters on the Moon have been named after Welsh scientists.

The crater Mee is named after Arthur Mee (1860-1926), the amateur astronomer, journalist, author, historian and educator from Cardiff. The crater lies on the southern part of the lunar Near Side, south of the Mare Humorum: it is a relatively large crater with disintegrated walls.

The crater Roberts is named after Isaac Roberts (1829-1904), pioneer astrophotographer (the crater actually honours both Isaac Roberts and Alexander W. Roberts, a South African astronomer, 1857-1938): it is situated on the Far Side of the Moon, close to the lunar North Pole.

The crater Wallace is named after Alfred Russel Wallace (1823-1913), the biologist and independent discoverer of the theory of evolution. It is found in the Mare Imbrium lava plain: the crater itself has been flooded with lava and only the top of the crater walls protrude above the Moon's surface.

The crater Wilkins is named after Hugh Percy Wilkins (1896-1960), lunar observer and cartographer. The crater lies in the southern uplands of the Near Side.

Features on Venus

A large number of features have been discovered on the surface of Venus through the use of radar mapping by spacecraft that have been put into orbit about about the planet. Where features have been named after people, these people have all been women in recognition of the female character of the goddess Venus in Roman mythology.

The crater on Venus called Rhys is named after the writer Jean Rhys (1894-1979), author of a number of books including The Wide Sargasso Sea.

A number of women's first names have been used for craters, taken from a wide range of countries and cultures. Among these is the crater Megan.

Arianrod Fossae is named after Arianrhod from the Mabinogi folk tales.


A number of features on Mars have been named after the words for Mars in various languages. These include the valley known as Mawrth Vallis.

There are craters on Mars named after Porth in the Rhondda and after Sarn.

Jupiter's satellites

There are areas on Europa, one of the Galilean satellites of Jupiter, called Dyfed Regio and Powys Regio: these have been named after the ancient kingdoms of Dyfed and Powys, not the more recent local government areas.

Features on Europa named after mythological characters include Amaethon, Gwern, Llyr, Pryderi, Pwyll, Rhiannon, Taliesin and Tegid. A feature on Callisto has been named Bran.


Minor planet 3634 Iwan is named after Iwan Williams, astronomer and specialist on small bodies in the Solar System.

Minor planet 1827 Atkinson is named after Robert Atkinson (1898-1982), the astronomer from Rhaeadr.


The Gazetteer of Planetary Nomenclature at the website of the United States Geological Survey provides a comprehensive list of names of features on Solar System bodies.


Bryn Jones wishes to thank Rhys Morris for providing useful information about the naming of astronomical bodies.

This page was created and is maintained by Bryn Jones.   E-mail: .
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