Big Brother 13 is the thirteenth season of the American reality television series, Big Brother. It began airing on July 7, 2011, on CBS and Showtime 2, and will conclude on September 14, 2011 when the winner will be determined. The format of the program will remain largely unchanged from previous seasons: a group of contestants, referred to as HouseGuests, are enclosed in the Big Brother House under the surveillance of cameras and microphones. Each week, the HouseGuests vote to evict one of their own until two HouseGuests remain on finale night. The winner will be decided by the last seven evicted HouseGuests, collectively known as the Big Brother Jury. Julie Chen will host the season premiere, evictions, and the season finale. The HouseGuests are competing to win a $500,000 grand prize with a $50,000 prize offered to the runner up. This season is being promoted as "The Summer of Double Trouble".
Big Brother 13 is produced by Endemol USA and Fly on the Wall Entertainment, with Allison Grodner and Rich Meehan returning as executive producers. This season of the program was announced on September 15, 2010, before the season finale of Big Brother 12 was transmitted, due to significant increases in the ratings over Big Brother 11. Casting for season began in mid-April with applications and video tape submissions that did not have a set deadline. Applicants chosen to be a finalist went to Los Angeles, California, from which applicants were narrowed down to a pool of 40 finalists. Robyn Kass, casting director for Big Brother, revealed on her Twitter account on June 8, 2011 that the semi-finalist were contacted while no final decision on who would be selected for the program. The selected group of HouseGuests were put into sequester on June 25, 2011 and interviewed by the media with their identities revealed on Yahoo TV on the morning of June 30, 2011. The 8 original cast members entered the house on July 2, 2011