Broadcast rally includes some Roman stars (5)
I believe the answer is:
astra
'roman stars' is the definition.
('stars' in Latin)
'broadcast rally includes some' is the wordplay.
'some' indicates the answer is hidden within the clue.
'ASTRA' is hidden in the letters of 'broadcast rally includes'.
(Other definitions for astra that I've seen before include "Car" , "Per ardua ad - - (RAF motto)" .)