Katy Perry’s Many Pop Star Pals (PHOTOS)

Katy Perry just scored another success with “E.T.”, making it the fourth number one single off of Teenage Dream. With all the hype surrounding the supernatural song’s music video release (not to mention the firework’s “alien entourage”), it’s easy to forget that the California songbird isn’t only a hit with alien life forms. The Adidas-wearing singer has got a way of connecting with those on planet Earth, too. From Rolling Stone cover girl Rihanna to Justin Bieber’s main squeeze Selena Gomez, check out the pop starlets who like to hang with Katy.