I was translating some random words when trying to figure out a name. Eventually I came across the word celestial. I like how it sounds because celeb means silver in LOTR's sindarin elvish language. See the connection: celestial (synonym to heavenly, stars are in "heaven"), celeb (silver, the color of stars).

Realizing this random(?) connection it made for a quite good pickup for a name. I'm a bit of a fan of LOTR, too. No, not such a fan I could talk elvish, just a few words have stuck with me, like celeb (for example in the name Celeborn, the husband of the elven queen Galadriel).

Oh, and then I just took the i away to make it a word of my own, celestal, still with the "soul" of the original word.

That's the etymology behind it. I actually didn't like it as my username at first but have since grown fond with it. In sindarin c is pronounced as a k, like in a word kite. But in celestial the c is pronounced like s in soft, for example. So my username can be pronounced either with a k or an s, whatever suits the best. Though I prefer pronouncing it with a k little more.