INTERACTING SUPERNOVAE AND SUPERNOVA IMPOSTORS: SN 2009ip, IS THIS THE END? by Pastorello, A, Cappellaro, E, Inserra, C, Smartt, S, Pignata, G, Benetti, S, Valenti, S, Fraser, M, Takats, K, Benitez, S, Botticella, M, Brimacombe, J, Bufano, F, Cellier-Holzem, F, Costado, M, Cupani, G, Curtis, I, Elias-Rosa, N, Ergon, M, Fynbo, J, Hambsch, F, Hamuy, M, Harutyunyan, A, Ivarson, K, Kankare, E