Apex domains cannot have CNAME records.
Question and response
Question
dig star.co.uk. NS
Answer
star.co.uk. 4 NS dns0.star.co.uk.
star.co.uk. 4 NS dns1.star.co.uk.
Authority
The response has no authority records.
Additional
dns0.star.co.uk. 4 A 185.77.72.10
dns1.star.co.uk. 4 A 195.245.201.35
dns0.star.co.uk. 4 AAAA 2001:67c:1088:0:0:0:0:10
dns1.star.co.uk. 4 AAAA 2001:a88:0:fffa:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0