Supernova Rate in Milky Way, why low?

[EdEarl]

 

Wikipedia

Only three Milky Way naked-eye supernova events have been observed during the last thousand years, though many have been telescopically seen in other galaxies. The most recent directly observed supernova in the Milky Way was Kepler's Star of 1604 (SN 1604), but remnants of two more recent supernovae have been found retrospectively.[1] Statistical observations of supernovae in other galaxies suggest they should occur on average about three times every century in the Milky Way, and that any galactic supernova would almost certainly be observable in modern astronomical equipment.[2]

Five supernova in a thousand years means the average time between them is 200 years. The current average for the observable Universe is three per 100 years = 33.3 years. Some may have occurred in the Milky Way that were not observed, but none were observed in the past hundred years. Even if we assume there were an average number in the 18th and 19th centuries, we are still deficit three or four. Is there some reason other than statistical variance that the Milky Way would be producing fewer than an average number of supernova? It seems possible this deficit may have allowed intelligent life to evolve. Is it known whether a some galaxies produce fewer supernova, for example based on the amount of hydrogen in a galaxy?

Edited March 26, 2016 by EdEarl

[J.C.MacSwell]

Five supernova in a thousand years means the average time between them is 200 years. The current average for the observable Universe is three per 100 years = 33.3 years. Some may have occurred in the Milky Way that were not observed, but none were observed in the past hundred years. Even if we assume there were an average number in the 18th and 19th centuries, we are still deficit three or four. Is there some reason other than statistical variance that the Milky Way would be producing fewer than an average number of supernova? It seems possible this deficit may have allowed intelligent life to evolve. Is it known whether a some galaxies produce fewer supernova, for example based on the amount of hydrogen in a galaxy?

Per Milkyway sized galaxy? Presumably?

 

Does it happen more at certain distances/epochs?

[Airbrush]

Maybe we miss seeing most of them because most of our galaxy is obscurred by dust clouds.

[EdEarl]

Maybe some, but they are so bright it seems others would light up the intergalactic dust, even if we couldn't view them directly.

[Raider5678]

I believe the reason is that since we are inside our own galaxy its hard to gain a full perspective of all thats happening in it. Since we are in our galaxy we can't very well see all the way to the other side, because we would have to see through a giant black hole, but most of it should be able to be seen because its mostly vacuum. But either way the way light from gravity if altered then our sight line would be down to about 1/4 of our galaxy, bringing the supernova rate from 33.3 years to about 132 years between each one we can see. And thats if the probability works 100% on the dot. since we are practically at the edge of our galaxy we can see other galaxys through whats beside us towards the edge, but inside not much

[Strange]

I believe the reason is that since we are inside our own galaxy its hard to gain a full perspective of all thats happening in it. Since we are in our galaxy we can't very well see all the way to the other side, because we would have to see through a giant black hole

 

The black hole is tiny. I'm not sure it could even be resolved by Hubble. The main reason we can't see a lot of the galaxy is because there is a lot of light and a lot of dust.

[Raider5678]

 

The black hole is tiny. I'm not sure it could even be resolved by Hubble. The main reason we can't see a lot of the galaxy is because there is a lot of light and a lot of dust.

Ok.