Starsailor B-sides describing celestial bodies (4)
I believe the answer is:
orbs
'celestial bodies' is the definition.
(I've seen this in another clue)
'starsailor b-sides describing' is the wordplay.
'describing' indicates a hidden word (describe can mean to go around).
'ORBS' is hidden in the letters of 'starsailor b sides'.
(Other definitions for orbs that I've seen before include "Spherical shapes" , "Spherical objects" , "Ball shapes" , "Jewelled spheres" , "sight" .)