Since the beginning of history , humanity has document celestial event . Chinese astronomers have been especially good at recording supernovae , having catalog 20 likely sightings over a couple of 2,000 years .

One of these sightings , a bright unexampled asterisk get a line in   386 CE , was think to be the lawsuit of the gorgeous supernova remnant G11.2 - 0.3 , but the latest observance from NASA ’s Chandra scope indicate that this is not the compositor’s case . Although this supernova take shape between 1,400 and 2,400 yr ago ( from our point of view ) , it would have been too faint to be visible .

Chandra had observed the objective in 2000 , 2003 , and 2013 , which allowed the researchers from North Carolina State University and New York University   Abu Dhabi toestimate preciselyhow quickly the nebula bequeath over from the supernova is expanding .

In a paper , publish in theAstrophysical Journal , the team judge that the prima fabric is incite at a hurrying between 700 and 1,100 kilometers ( 435 to 680 air mile ) per secondly .

Although it might not have been documented historically , G11.2 - 0.3 is still a very special object . It is believed to be one of the youngest have intercourse exemplar of a heart - collapse supernova . These types of stellar detonation fall out at the close of a sensation ’s life , when the star is not releasing enough energy to equilibrize out its mass , and it break up under its own weight .

The collapse is catastrophic . The marrow is compressed so much that it forms a pulsar , a speedily - spin neutron star , and the release of vigour blows the outer layer of the star aside to work a   nebula .

In the character of G11.2 - 0.3 the nebula looks very circular , but astronomers were able-bodied to show that appearances are deceptive . The gas is moving unequally . The scientists call up the burst was quite spotty , but subsequent stellar   winds either from the pulsar or from a fellow hotshot helped speed up some of the gas , and the nebula ended up looking very symmetric .

So the supernova seen in 386 CE run back to being an unproven observation , but G11.2 - 0.3 is by all odds one for the history books .