An art auction conceived by U2 frontman Bono and British artist Damien Hirst has raised $US42.5 million ($46.8 million) in New York for UN-backed health programs in Africa.The auction, which drew Hollywood celebrities, supermodels and rock stars, was described as the largest charity event ever mounted and will help keep thousands of AIDS patients on antiretroviral drugs for years to come.Artists such as Georg Baselitz, Howard Hodgkin, Jasper Johns, Anish Kapoor and Jeff Koons contributed works for the red-themed Valentine's Day sale, which raised far more than the upper pre-sale estimate of $US29 million.Proceeds from the sale, organised by Bono's charity organisation (RED), are to go directly to the United Nations Foundation to support HIV/AIDS relief programs run by The Global Fund to Fight AIDS, Tuberculosis and Malaria."I have watched people dying for lack of these pills," Bono said after the sale. "I actually can't quantify how many people that will keep alive."It's not just the money we made tonight, it's the excitement around the issue," he added.Auctioneer Oliver Barker described the evening as "the most extraordinary sale ... It was just extraordinary. We are completely thrilled."Several artworks went for three or four times their upper estimates, with several lots sparking frenzied bidding. Among the buyers was supermodel Christy Turlington, who attended the auction with her husband, actor Ed Burns.Others in the audience included Tennis legend John McEnroe, supermodel Helena Christensen and Hollywood actor and director Dennis Hopper.Hirst put seven artworks into the sale, which sold for more than $US19 million in total.Among the auction highlights were his Where there's a will..., which sold for $US7.1 million, and his All You Need Is Love - a red, heart-shaped butterfly painting, which fetched $US2.4 million.Jeff Koons' Balloon Rabbit Wall Relief (RED), sold for just over $US2 million, while records were set for 17 artists including enigmatic British graffiti artist Banksy.The auction brought funds raised by Bono's (RED) organisation since it was started last year to more than $US100 million.