U2 frontman Bono will go under the hammer next month, when an oil painting showing him receiving an honorary knighthood is auctioned in Dublin. The artwork, painted by Irish artist David Nolan, is expected to fetch as much as $4,000 (GBP2,000) when it goes under the hammer. The painting is based on a photograph taken by Julien Behal, who captured the moment the frontman accepted the honour. Bono was handed the honour in March (07) in recognition of his contribution to music and his humanitarian work, particularly in Africa. Artist Nolan has been responsible for a handful of paintings of high-profile figures, including Democratic Unionist Party leader Ian Paisley.