Who is the undisputed queen of Pop in the present time? Have you ever wondered? Rolling Stone, a U.S.- based magazine devoted to music, liberal politics, and popular culture, has come up with an index of 16 solo female artists. It ranked the artists on the basis of six criteria including album and digital song sales, Hot 100 rankings, radio airplay, YouTube views, social media, concert grosses, industry awards and critics' ratings.

The competitors are (in alphabetical order): Adele, Christina Aguilera, Beyoncé, Kelly Clarkson, Miley Cyrus, Ke$ha, Lady Gaga, Nicki Minaj, Katy Perry, P!nk, Rihanna, Robyn, Shakira, Britney Spears, Taylor Swift and Carrie Underwood.

The time period covered for the selection procedure is from 2009 to mid-2011.

Below are the 16 glamorous pop stars according to their rankings:

Singer Lady Gaga arrives at an album signing event for her new release Born This Way at Best Buy in New York City May 23, 2011. REUTERS/Jessica Rinaldi