On the Emergence and Discovery of Hot Spots in Supernova Remnant 1987A
  We present the discovery of several new regions of interaction between the ejecta and equatorial circumstellar ring of SN1987A, an interaction leading to a much expanded development of the supernova remnant. We also trace the development of the first such "hot spot," discovered in 1997, back to 1995. Later hot spots seem to have emerged by early 1999. We discuss mechanisms for the long delay between the first and later spots. 
Stephen Lawrence (1), Ben Sugerman (1), Patrice Bouchet (2), Arlin   Crotts (1), Robert Uglesich (1) and Steve Heathcote (2)...