NO ARCTURUS ORIGIN FOR ARTHUR NAME

Occam's Razor strikes again.

Before allowing my theorizing to be influenced by the notion expressed in the following article -

https://mistshadows.blogspot.com/2025/05/throwing-bear-wrench-in-works-new.html?m=1

- I decided to take the proposed Arcturus origin for the name Arthur to a Welsh expert, viz. Dr. Simon Rodway. Our discussion of the possible etymology follows in unedited form:

Simon, 

Several Arthurian scholars (like Thomas Green in Concepts of Arthur) and Latinists (like Benet Salway) are claiming that a second possible derivation for Arthur is Arcturus, the "bear-guard" star.

Is this possible, from the standpoint of Welsh language development?

Thank you.

D.

It could work if it was borrowed from a form in which the first consonant cluster was simplified to rt (i.e. *Arturus) and if the first u was short (like the oo sound in good).

Simon

All the dictionaries have it as long. So, no?

Lewis and Short:

arctūrus, i, m., = ἀρκτοῦρος.

Well, there's a difference between Classical vowel lengths and what you find in various registers of spoken Latin, so I wouldn't say impossible. As for the combination -rct-, I don't really know what would have happened to it. I suspect it would be simplified (cf. common English pronunciation of Antarctica as 'Antartica'). In the case of sanctus with a broadly similar combination we see two treatments: > santus > sant (cf. santo in Italian etc.) or > *sactus > seith. A bigger question is whether Arcturus was ever used as a personal name.

Simon

It was not used as a name. Nor is there an attested Arcturius.

The suggestion is that Arcturus was applied as a nickname.

I'm not finding this very convincing.

No, me neither. There is a perfectly normal development from Artorius from Arthur, which I've demonstrated for you before.

Simon