Subsequently, we’ve meticulously observed the expanding, evolving remnant.

This image shows the supernova remnant of SN 1987a in six different wavelengths of light. Even though it’s been 36 years since this explosion occurred, and even though it’s right here in our own backyard, the material around the central engine has not cleared enough to expose the stellar remnant. For contrast, Cow-like objects (also known as fast blue optical transients) have their cores exposed almost immediately. (Credit: Alak Ray, Nature Astronomy, 2017; ACTA/ALMA/ESO/Hubble/Chandra composite)

On the outskirts, gaseous shells blown off centuries earlier continue expanding.

The remnant of supernova 1987a, located in the Large Magellanic Cloud some 165,000 light years away. It was the closest observed supernova to Earth in more than three centuries, and reached a maximum magnitude of +2.8, clearly visible to the naked eye and significantly brighter than the host galaxy containing it. (Credit: ESA/Hubble & NASA)

Interior to them, supernova shockwaves heat a spheroidal halo of material.

Hubble’s optical light observations of Supernova 1987A become even more valuable when they are combined with observations from telescopes that can measure other kinds of radiation from the exploding star. The image shows the evolving images of hot spots from the Hubble Telescope alongside images taken at approximately the same time from the Chandra X-ray Observatory and the Australia Telescope Compact Array (ATCA) radio observatory. The X-ray images show an expanding ring of gas, hotter than a million degrees, that has evidently reached the optical ring at the same time as the hot spots appeared. The radio images show a similar expanding ring of radio emission, caused by electrons moving through magnetized matter at nearly the speed of light. (Credit: R. McCray (University of Colorado), D. Burrows and S. Park (Pennsylvania State University), and R. Manchester (Australia Telescope National Facility))

Energy injection causes irregular changes in brightness, X-rays, and radio emissions.