EXPLICIT SELF-DUAL METRICS ON CP2= ... =CP2

We display explicit half-conformally-flat metrics on the connected sum of any number of copies of the complex projective plane. These metrics are obtained from magnetic monopoles in hyperbolic 3-space by an analogue of the Gibbons-Hawking ansatz, and are conformal compactifications of asymptotically-flat, scalar-flat Kahler metrics on n-fold blow-ups of C2. The corresponding twistor spaces are also displayed explicitly, and are observed to be Moishezon manifolds - that is, they are bimeromorphic to projective varieties.