In the Spanish translation, which I am reading, it opens with "an old Irish children's song:"
En la noche brilla tu luz.
De dónde, no lo sé.
Tan cerca parece y tan lejos.
Cómo te llamas, no lo sé.
Lo que quiera que seas: luce, pequeña estrella.
In the English translation, it opens with a familiar children's rhyme:
Twinkle, twinkle, little star.
How I wonder what you are !
Up above the world so high,
Like a diamond in the sky.
--Jane Taylor (1783-1827)
The Spanish translation is not close to being a translation of this rhyme, and Taylor was English, not Irish.
What poem is used in the original German version?