Old Stars

[Manuel I Komnenos]

In the night sky we can see thousands, even millions of stars of which some are said to be in the late stage of their life..

Is it possible that some of those stars that we can currently see have ceased to exist?
The distance is obviously great and we see those stars the way they were before some million years.
What if the star we are looking at was destroyed before millions of years and we could see the explosion tomorrow for example? Would that light from the explosion affect earth in any way? Or the gamma rays?

[Sphere]

In the night sky we can see thousands, even millions of stars of which some are said to be in the late stage of their life..

Is it possible that some of those stars that we can currently see have ceased to exist?
The distance is obviously great and we see those stars the way they were before some million years.
What if the star we are looking at was destroyed before millions of years and we could see the explosion tomorrow for example? Would that light from the explosion affect earth in any way? Or the gamma rays?

Absolutely. Not only are we seeing star's that no longer exist, we are looking way back in time into the early formation of the universe, not long after the Big Bang (as far back as when the universe was .0044% of its current age, which is mind blowing). Also, the explosion of stars is so frequent, that certain supernova are used as "standard candles" by which we can judge how far away the galaxy containing the supernova is from us.

Here is furthest galaxy we have ever seen, we are seeing it how it looked 600 million years after the big bang, and considering the Big Bang occurred 13.75 trillion years ago and the average life cycle of a star is 5 Billion years, the stars in this galaxy have exploded and reformed ~2750 times in the time it has taken this image to reach us.





Here is a picture of an actual supernova occurring on the edge of a galaxy...

[Frederich Barbarossa]

Absolutely. Not only are we seeing star's that no longer exist, we are looking way back in time into the early formation of the universe, not long after the Big Bang (as far back as when the universe was .0044% of its current age, which is mind blowing). Also, the explosion of stars is so frequent, that certain supernova are used as "standard candles" by which we can judge how far away the galaxy containing the supernova is from us.

Here is furthest galaxy we have ever seen, we are seeing it how it looked 600 million years after the big bang, and considering the Big Bang occurred 13.75 trillion years ago and the average life cycle of a star is 5 Billion years, the stars in this galaxy have exploded and reformed ~2750 times in the time it has taken this image to reach us.





Here is a picture of an actual supernova occurring on the edge of a galaxy...

13.7 billion years actually. And In reality if we think about it, we are only around the 2nd or the beginning of the 3rd generation of stars, because if you think about it, it takes 5 billion years for a star to live and we've only been in the universe for 13.7 billion years. Obviously we are young. So what occurred before?

[Phier]

13.7 billion years actually. And In reality if we think about it, we are only around the 2nd or the beginning of the 3rd generation of stars, because if you think about it, it takes 5 billion years for a star to live and we've only been in the universe for 13.7 billion years. Obviously we are young. So what occurred before?

The early super giant stars die a much faster death, the biggest my last only a few 100k years.

We are without a doubt 2nd generation because we have heavy elements, but are most likely more than that.

[xcorps]

If the Sun were to suddenly cease to exist, it would take 8 minutes for you to find out.

[Lord Rahl]

http://en.wikipedia.org/wiki/SN_1006

[Gordon Freynman]

What if the star we are looking at was destroyed before millions of years and we could see the explosion tomorrow for example? Would that light from the explosion affect earth in any way? Or the gamma rays?

Unless it's really close (i.e. within a few thousand light-years away) then the only effect on Earth it will have is giving us something new and interesting to look at in the night sky.

[Cesarz]

Unless it's really close (i.e. within a few thousand light-years away) then the only effect on Earth it will have is giving us something new and interesting to look at in the night sky.

How long would it be there for us to look at?

[Gordon Freynman]

How long would it be there for us to look at?

Supernovas are typically visible for a few weeks to a few months.