general relativity - Does Hawking radiation need an apparent horizon and when does it switch on during stellar collapse?

I've read that Hawking radiation is implicitly linked with the existence of an apparent horizon (1). This seems a slightly less onerous than linking Hawking radiation with a genuine bona fide event horizon and its dependence on the global spacetime properties.

However I've also read a number of papers that seem to me to suggest than Hawking radiation occurs during stellar collapse and can occur in, albeit physically implausible models, before an apparent horizon forms or even when an apparent horizon is miraculously avoided (2).

So my question is: what is the connection between Hawking radiation and the apparent horizon and for a far-off observer watching a star collapse, when would they observe Hawking radiation to "switch on"?