'The X Factor': Rihanna to debut as guest mentor

First she was judged the "Sexiest Woman Alive." Now R&B star Rihanna gets her chance to do the evaluating as she she joins "The X Factor" for four episodes beginning Wednesday (Oct. 12).

The "Umbrella" singer will partner up with "L.A." Reid to figure out which of the group will make it to the next round. This isn't the first time Rihanna has worked with Reid. He signed the singer back in 2005. She's since gone on to have five multi-platinum albums. Rihanna is also no novice to this judging role having done it on the U.K. version of the show.

The program will also reveal the other celebrity mentors who will work alongside the shows other judges, Paula Abdul, Simon Cowell and Nicole Scherzinger.

"The X Factor" airs at 8 p.m. ET.