Heart of Fire

In Elvish, the more usual names for the Sun were Anar (in Quenya) or Anor (in Sindarin), deriving from a word for 'fire' (and indeed in some sources translated 'Heart of Flame'). The Noldor gave the Sun another name, Vása, which literally meant 'that which consumes', but was also interpreted as the 'Heart of Fire'.

This name among the Noldor is not recorded in actual use, but there is a hint of its meaning that dated back the making of the world. When Ilúvatar showed the Ainur his Vision of the world to come, and then made it real, the Ainur saw it as having a 'living heart of flame' (in Ainulindalë, where this heart of flame is implied to have some association with the mysterious Flame Imperishable). The wording of this myth is poetic and ambiguous, so the meaning is difficult to tease out, but the implication seems to be that the Heart of Fire is intended as much more than simply a hot burning flame.

Gandalf seemed to reinforce this connection on the Bridge of Khazad-dûm, when he announced himself as both a 'servant of the Secret Fire' and a 'wielder of the flame of Anor [the Sun]' (The Fellowship of the Ring II 5, The Bridge of Khazad-dûm). Again, these references are somewhat opaque, but they do seem to suggest that the Sun (or the Heart of Fire) being described is much more than merely a shining fiery light in the sky.