CHICAGO (CBS4) — Thousands of Oprah Winfrey fans are expected in Chicago for a star-studded, double taping of her talk show as it approaches its finale.

The show dubbed “Surprise Oprah! A Farewell Spectacular” starts Tuesday evening at the United Center, just blocks from Winfrey’s long-time studios. Winfrey’s producers say the guest lineup is a secret, but they promise “the biggest names in movies, music and television.”

READ MORE: Facing South Florida: 1-On-1 With Miami-Dade Mayor Daniella Levine Cava

Tickets were free and distributed to fans through a lottery. The episodes will air May 23 and 24, before Winfrey’s final show on May 25.

READ MORE: Miami Gardens Faith Leaders, Officials & Community Members Come Together To Remember Lives Lost To Gun Violence

Executive producer Sheri Salata says Winfrey is “in great spirits, energized and taking in every last bit of these final days.”

Winfrey announced in November 2009 that she would end “The Oprah Winfrey Show” this year after 25 years.

MORE NEWS: Orange County Officials Searching For 19-Year-Old Miya Marcano

(© 2011 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)