A country star has now turned around (5)
I believe the answer is:
sudan
'a country' is the definition.
(I know that Sudan is a country)
'star has now turned around' is the wordplay.
'star' becomes 'sun' (the Sun is a star).
'has' indicates putting letters inside.
'now' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
'turned around' is a reversal indicator.
'ad' back-to-front is 'da'.
'sun' going around 'da' is 'SUDAN'.
(Other definitions for sudan that I've seen before include "Recently-split country" , "Country divided by the Nile" , "Country south of Egypt" , "Country between Egypt and Zaire" , "Country in NE Africa, capital Khartoum" .)