The forward will then be forced to return to Pompey, as a an 'emergency loan' cannot go beyond a 93 day period.
Keene said: "It's great to be playing first team football and I'm really enjoying my time at Bournemouth.
"I feel I've fitted in well with the rest of the lads and I'm really enjoying my football here.
"It's been great to get among the goals and contribute to some good team performances, I'm definitely looking to score a few more goals for the team before my loan is up".