Goddess with a heavenly body (5)
I believe the answer is:
venus
I believe this clue is a double definition.
'goddess' is the first definition.
(Roman goddess of love)
'heavenly body' is the second definition.
(Venus is an example)
'with a' is the link.
(Other definitions for venus that I've seen before include "Morning star" , "our Neighbour" , "Brightest planet" , "Second nearest planet to the sun" , "Roman counterpart of Aphrodite" .)