Durin's Crown

"He stooped and looked in Mirrormere
And saw a crown of stars appear"

― Gimli singing the Song of Durin in Moria.¹

Durin's Crown was a constellation in the northern hemisphere of Arda. It appeared as a crown above Durin's reflection in Mirrormere, which he saw as a good omen. He built Khazad-dûm in the valley. Ages later, in T.A. 3019, Gimli, Frodo and Sam looked in the lake, but whether they saw the crown is unclear².

Most people think Durin's Crown is another name for Valacirca. Tolkien does not state what it looks like, but seven stars appear on the Doors of Durin. This led Steve Gardner to conclude that it could also have been Auriga or the Northern Crown³.

References

1. The Fellowship of the Ring, A Journey in the Dark.
2. The Fellowship of the Ring, Lothlórien.
3. Vinyar Tengwar 13, page 3.