Valacirca
Valacirca (Q. "Sickle of the Valar") was one of the constellations set in the heavens by Varda to enlighten the awakening of the Elves and gathered by Varda from among the ancient stars1.
Valacirca is by far the most important constellation in the heavens of Arda. It is also the first to appear in the mythology that J.R.R. Tolkien begun to develop in the 1910's2.
Other names
In Sindarin, the name was translated as Cerch i-Mbelain. The names Otselen and Edegil were also used in reference to the seven stars of the constellation. Hobbits called it the Burning Briar. The constellation is also known as the Plough, a name used in British English to refer to the seven brightest stars in Ursa Major3, known in US English as Big Dipper. It is unclear whether the Dwarvish constellation Durin's Crown, seen in the reflection of Mirrormere, is the Valacirca.