Help UFO fancier to be optimistic (7)

I believe the answer is:

hopeful

I'm a little stuck... Click here to teach me more about this clue!

'optimistic' is the definition.
(similar in meaning)

'help ufo fancier to' is the wordplay.
'help ufo' can be anagrammed to 'HOPEFUL'.
However, I'm not clear how this is indicated.

'be' acts as a link.

Can you help me to learn more?

(Other definitions for hopeful that I've seen before include "Prospect" , "Wannabe" , "Optimistic, expectant" , "One wishing to succeed" , "Promising success" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app