Why we’ve only seen 5 Milky Way supernovae in the last millennium?
Scientists estimates that probably fifty stars died in Milky Way during the last millennium (thousand years). That will be approximately one supernova in every two decades.
Yet it’s already been four hundred years since the last supernova was observed. So why we haven’t seen any supernovae in all those years?
Now, a team of scientists in their new research has explored some possible reasons for this- it could be due to all supernovae happened at the wrong places or space dust obscuring light coming from these celestial fireworks or it just could be our bad luck.
The last documented supernova dubbed Kepler’s supernova was occurred in October 1604. Back then nobody knew how these new stars were appearing and disappearing from our sky.
Even though since Kepler’s supernova we have advanced so much in technology, but still we haven’t detected any supernova going off. Does Milky Way is not producing any supernova events?
According to the research team that shouldn’t be the case. The Cassiopeia A nebula- a remnant of supernova did go off some 350 years ago, but it wasn’t noticed by anybody.
Most supernovae happen in the thin, star stuffed Milky Way’s disk, the region with most of the dust, which blocks light signals, making them almost impossible to see.
Again, a region with lot more dust, the core of Milky Way is known to host more than average supernova events. And here too dust blocks the light signals.
To be seen with naked eyes, the supernova event needs to happen at the right location within the Milky Way. It should be close enough with unobstructed view.
If we combine these effects with the estimated supernova rate, it replicates the documented record of observable supernova events.
But, as per scientific model, most of the naked eye supernovae should happen near the galactic centre’s direction. Yet most of the documented supernova events completely avoided this region.
It could be due to the impact of Milky Way’s spiral arms, where clumping of stars could produce their own events, which scientists hope to investigate in future.