Picture globe that radiates light and heat (11)

I believe the answer is:

photosphere

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

'picture globe that radiates light and heat' is the definition.
The definition suggests a singular noun which matches the answer.

'picture globe' is the wordplay.
'picture' becomes 'photo' (a photograph).
'globe' becomes 'sphere' (I've seen this before).
'photo'+'sphere'='PHOTOSPHERE'

Can you help me to learn more?

I've seen this clue in The Daily Express.

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