Where does “Tysnes” come from?

Tysnes (Norwegian Nynorsk) comes from Old Norse Týsnes, from Old Norse Týr, from Proto-Germanic Tīwaz, from Proto-Indo-European deywós, from Proto-Indo-European dyew- — to be bright; sky, heaven.

Ancestry of “Tysnes”, step by step

Step	Language	Word	Meaning
1	Old Norse	Týsnes	—
2	Old Norse	Týr	Tyr
3	Proto-Germanic	Tīwaz	of Tiw; god; Tyr, god of war
4	Proto-Indo-European	deywós	god
5	Proto-Indo-European	dyew-	to be bright; sky, heaven

Every word from Proto-Indo-European dyew- →Every word from Proto-Indo-European deywós →Every word from Proto-Germanic Tīwaz →