We don't see all of the Milky way as is, like the other side of the milky way is out of our view. https://www.universetoday.com/23173/the-milky-way-from-earth

We don't see all of the Milky way as is, like the other side of the milky way is out of our view. https://www.universetoday.com/23173/the-milky-way-from-earth/ https://www.universetoday.com/23173/the-milky-way-from-earth... So that metric could be correct, but the supernova is outside of what we see.