So my understanding is that stars are born and die all the time with supernovae, black holes, etc. And we can see this in deep space all the time but why can’t we see that with the naked eye? Why are our constilations the same as when I was a child? If stars are born and die all the time in our universe Why don’t we have a new night sky every few decades? I know a stars life is long so not all stars will change in my life time but there’s no new ones born or no old ones that die close enough for us to see when we look up
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Stars are *extremely* long-lived. An average star has a lifetime well into the billions of years (the Sun is a relatively large star, larger stars have shorter lifetimes, and the Sun’s lifetime is ~10 billion years). Stars you can see happen to be larger and brighter than average, but even among the stars you see, the average lifetime is something like a billion years.
Since you can see perhaps a thousand stars in a very dark sky (and much less if you live in a city), that means you’d expect to see one of the thousand stars in your sky die only once every million years or so (1000 stars * 1 star / 1 billion years). Stars are born at a similar rate – that is, the number of stars in the sky is relatively stable over time – so you’d expect to see a new star roughly this often, too.
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