10 pages, including 7 b/w + 1 color embedded EPS figures; uses
  aipproc.cls . To appear in "Supernova 1987A: Twenty Years After: Supernovae
  and Gamma-Ray Bursters", edited by S. Immler, K. W. Weiler and R. McCray,
  American Institute of Physics, New York, 2007, in press. Updated figure 2