Anonymous
Anonymous asked in Science & MathematicsAstronomy & Space · 9 years ago

Could a lot of the stars in the galaxy potentially be gone?

For example, Alnitak, Alnilam and Mintaka (the three stars that make up Orion's belt) are between 800 and 1400 light years away, so technically we are seeing those stars what they looked like 800-1400 years ago. Is it possible that those stars aren't even there anymore?

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  • 9 years ago
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    Actually, most of the stars seen with the naked eye are still there. The life span of stars is in the billions of years on average, and only the very largest and most massive measure their lives in millions of years. Our life spans are so short that we have to rely on historical records such as those of ancient China to see what has changed from our perspective.

  • Jared
    Lv 7
    9 years ago

    yes, most stars you see in the night sky are probably "not there anymore"...now I use quotes, because Einstein tells us that there is NO such thing as simultaneity, that is you CANNOT say that event A and event B happen at the same time (if they are separated by space), so it's not totally correct to even say that "right now" they are not there, because "right now" has no meaning at such a large distance.

    Edit:

    Supernovas are observed around a couple of times a century, there was one observed, I believe in the 1980s or 90s. Yes, major ones, that are visible to the naked eye are very rare.

    Edit: I will recant, in that, I think the other responders make good arguments that most of the stars probably are there...however, I'm still quite sure that A LOT of them (but probably NOT most) are no longer there. The fact that stars last for millions or billions of years isn't important.

    We are observing stars at all ranges of their life time, so we could be observing stars that are say only 1 million years old (in this case, it's not likely that it's burnt out yet)...but we could certainly observe a star that was there prior to the Sun being created and we are seeing the tail end of its life...so the idea that virtually all stars are still there seems a little absurd to me, if we assume the starlight we see is from when the star first formed, then yes, the Milky Way's diameter means it hasn't had time to die off yet...but that's completely ignoring the fact that the star could have been there a long time before, so there is still a good probability that several stars we see in the night sky are no longer there.

  • DLM
    Lv 7
    9 years ago

    No.

    Not even close.

    Every star in the Milky Way galaxy is within 100,000 light years from us. The shortest lived stars still last over millions of years, up to hundreds of millions, while the sunlike stars last for billions of years, and red dwarfs for possibly trillions of years. Virtually every single star you can see in the night sky today, is still fusing... it is still there. There are two or three possible exceptions... stars a great distance from us that are near the end of their life. Betelgeuse in Orion is one of these candidates, but still, within 1000 light years, and somewhere in the last half million years of its life... it is unlikely that even that star has already gone supernova.

  • 9 years ago

    Actually I'm gonna give you a completely different answer......there's another theory slightly different I'm gonna tell you about that might shock you a little and it's something I believe personally. Some physicists think there's an embalance between matter and dark matter and astronomers havbe their beliefs as well. then theres a group of science that believes that what we see isn't exactly what is actually there...Somehow there's a huge accumulation of dark matter and a smaller amount of stars and matter..but we cant's see the dark matter....when it might be the other way around.. Somehow there might be a formula that allows light to bounce around gravity alot more in space other than the excuse of gravity bending light,..."it might be caused by pressure waves and bubbles of pressure" and pressure differences between areas of space. This can be expressed in experiments done on earth with mirages and explosive wave fronts as they tend to reflect light readily....So, any pressure surface might act as a reflector or mirror and also might act like a pattern reflector "which in this case" actually works perfectly because we tend to see patterns of stars in space such as circles and spctrums of light in circle patterns of stars in far out in space. Pressure waves form in space for various reasons, Novas, gas bubbles, gravity pockets, scattered physical matter,etc. So if we observe stars from a long distance and we see a great many stars and we assume that they must be there and have been for a very long period of time,...are they really?.....could it be possible that they are pin points of light that are reflections instead from nearby stars or stars that are in a along a clear pathway from another point in space?....I think that's possible. I think that would account for alot of missing and incomplete science astrnomers are still trying to figure out....but that's just my opinion..and the opinion of a growing number of other people.....who knows? we could be right...the one thing we have going for us is that pressure fronts in space don't travel fast and they tend to last hundreds of millions of years and experiments on earth can be captured on film or on computer screens.

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  • GeoffG
    Lv 7
    9 years ago

    While this is remotely possible, it is very unlikely because the time which it takes the stars' light to reach us is very short, no more than a few thousand years, compared to the lifetimes of the stars, measured in billions of years.

  • 9 years ago

    Yes, but whereas that's possible in the sense that only their light is available as evidence for their existence, the same is often true of any object you've seen but has never been touched, such as a cloud, an unclimbed mountain peak, or even the inside of a freshly cut melon or just-falled snow. It's just that the delay is greater.

  • Anonymous
    9 years ago

    Actually the closest star in the belt is 1,100 ly away.

    1,100 to 1,400 ly. away.

    All of these are blue super giants which have short life spans, but it is still millions of years. To say that we just happen to be living in the period of just one of them going supernova would be coincidence. Since the last supernova observed in the Milky Way Galaxy was in 1066 we can assume that most of the stars visible in the naked eye sky are still there.

    However if instead of saying our galaxy, you say the universe, astronomers can see a different supernova in some distant galaxy every day. Distant galaxies would look very different in reality if we could instantly teleport to there, then what their appearance to us looks like here on Earth.

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