1 E.A. Michael, R.A. McCray, C.S.J. Pun, P.. Garnavich, P.M. Challis, R.. Kirshner, J.C. Raymond, K.J. Borkowski, R.A. Chevalier, A.V. Filippenko, C.. Fransson, P.. Lundqvist, N.. Panagia, M.M. Phillips, G.. Sonneborn, N.B. Suntzeff, L.. Wang, and J.C. Wheeler, The Astrophysical Journal 542, (2000).