The supernova of 1987 finally begins to fade

Almost thirty years after Supernova 1987a became the first naked eye supernova since the invention of the telescope, the necklace ring of spots that the explosion’s shockwave ignited in the late 1990s are finally beginning to fade.

But now the hotspots have slowly begun to fade, Claes Fransson (Stockholm University, Sweden) and colleagues report in the June 10th Astrophysical Journal Letters. The team studied images taken by the Hubble Space Telescope from 1994 to 2014, and spectra from the Very Large Telescope spanning 2000 to 2013. Based on the rate at which the hotspots are fading, the researchers predict the glittering necklace will fade away sometime between 2020 and 2030, with the calculations favoring closer to 2020. The clumps of gas in the central ring are likely dissolving, thanks to a combination of instabilities and conduction in the hot gas surrounding the clumps. In other words, the central ring is being destroyed.

The show really isn’t over. The aftermath of a star exploding goes on for thousands of years. So to will SN1987a’s show.

A supernova twenty-five years later.

A supernova twenty-five years later.

SN 1987A, it turns out, was like a dust-bomb, with estimates of the total dust it threw into space, based on the infrared brightness of the dust … implying enough dusty material to build the equivalent of 200,000 Earth-mass planets. Mingled within the dust are elements as diverse as oxygen, nitrogen, sulphur, silicon, carbon and iron. This immense amount of dust has been beyond expectations and, if all supernovae spew out this much dust, it helps explain why young galaxies that we can see existing in the early Universe, which have high rates or star birth and death, are so dusty. The dust, however, isn’t a nuisance to be wiped away – this is the material that goes into building new planets, moons and even life. The iron in your blood and the calcium in your bones all came from supernovae like SN 1987A, as mostly did the oxygen we breath and the carbon in our constituent molecules.