From Tolkien Gateway

Morwinyon or Morwinthi is a star named in the earliest tales of Tolkien's legendarium. Christopher Tolkien identified it as Arcturus, the third brightest individual star visible in the Northern Hemisphere with an orange-yellow colour.

In "The Coming of the Elves and the Making of Kôr", Manwë suddenly became aware that the Elves had awoken. Their arrival prompted Varda to create new stars to double the glory of the sky. At the end of this task Varda was returning in great haste to Valinor and she dropped Morwinyon in the west where it blazes above the world's edge.[1]

In "The Tale of the Sun and Moon", it was said that jewel-makers caught their inspiration from the stars and "not least did they love Morwinyon of the west, whose name meaneth the glint at dusk."[2] In the commentary on this section of The Book of Lost Tales Part One, Christopher Tolkien noted that Morwinyon was identified in both the Qenya and Gnomish word-lists as Arcturus. Strangely, it is represented as always being in the western sky. Apparently in the ancient myths of the Elves not all heavenly bodies moved from East to West.[3]


In the Qenya Lexicon, Morwinyon derives from two roots: MORO ("glint in the dark"), and GWINI, with a derivative word wintil ("a glint"). The Gnomish version is Morwinthi, probably connected to gwim or gwinc ("spark, flash") or gwimla ("wink, twinkle").[4]


Middle-earth Cosmology
 Constellations  Anarríma · Durin's Crown · Menelmacar · Remmirath · Soronúmë · Telumendil · Valacirca · Wilwarin
Stars  Alcarinquë · Borgil · Carnil · Elemmírë · Helluin · Luinil · Lumbar · Morwinyon · Nénar · Star of Eärendil · Til 
The Airs  Aiwenórë · Fanyamar · Ilmen · Menel · Vaiya · Veil of Arda · Vista
Narsilion  Arien · Moon (Isil, Ithil, Rána) · Sun (Anar, Anor, Vása) · Tilion
See also  Abyss · Arda · Circles of the World · · Timeless Halls · Two Lamps · Two Trees · Void