PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

the sphere of the fixed stars ‘the sphere of the fixed stars’

English

References: Alm. Toomer: 38. – PH Hamm: I.5:3, 48:13-14
Translation of:
Greek: ἡ τῶν ἀπλανῶν ἀστέρων σφαῖρα [Alm. Heiberg: I.2, 9:23-24]
Greek: ἡ τῶν ἀπλανῶν σφαίρα [PH Heiberg: I.5:3, 76:28]