Imaged by the Hubble Space Telescope, the active Seyfert galaxy NGC 4051 has hosted at least three supernovae since 1983 that were visible to ground- or space-based telescopes on Earth.
New observations of the remnant of supernova (SN) 1987A are confirming supercomputer model predictions made at Caltech that the deaths of stellar giants are lopsided affairs in which debris and the stars’ cores hurtle off in opposite directions.