Astronomer noted focal point has odd bulge (6)
I believe the answer is:
hubble
'astronomer' is the definition.
(I know that Hubble is a astrophysicist)
'point has odd bulge' is the wordplay.
'point' becomes 'hub' (I have seen 'Focal point ' mean 'hub' so perhaps 'point' could also mean 'hub').
'has' says to put letters next to each other.
'odd' indicates alternate letters.
The alternating letters of 'bulge' are 'ble'.
'hub'+'ble'='HUBBLE'
'noted focal' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for hubble that I've seen before include "Astronomer; name of telescope" , "Space telescope - American astronomer" , "US astronomer, his Constant" , "[LAWMAKER] ?" , "Hookah" .)