are we looking into the past, could it be that the star we took a picture of doesn't exist anymore....and ... if one exploded would we see a flash of light, when it reached us?
2007-01-28 11:56:50 · 5 answers · asked by Jerry 2 in Science & Mathematics ➔ Astronomy & Space
Yep, they might not exist anymore. But it takes a long time for stars to die, and we know about it ahead of time - they go through distinct phases.
Yes, we often see supernova. I'm looking for one tonight actually. They aren't just a flash - they last days, weeks, months.
2007-01-28 12:01:35 · answer #1 · answered by eri 7 · 0⤊ 0⤋
Yes, it is possible it doesn't exist anymore. The image we take a picture of is from the past depending on how far away the star is. For example, if it's 100,000 light years away, then what we are seeing happened 100,000 years ago. If it did explode, we would see it when the light reached us, 100,000 years after it happened.
2007-01-28 20:08:34 · answer #2 · answered by crazydave 7 · 0⤊ 0⤋
Well now, let me see...
If we talk about the Sun (it is a Star), light from the sun takes
about 8 minutes to reach the Earth. that is because it is only
93,000,000 miles away.
Alpha Proxima is 4.3 Light Years away from the Sun. So light
from it, takes 4.3 years to reach us. If something happened
there right now, we would not see any sign of that for 4.3
years. Then, if you happened to look at that star, you might see
what happened 4.3 years ago. Clouds and storms here on the Earth could block your view, and make it impossible to see for
periods of time. And, of course, you would have to know what to expect to see each time you looked in that direction to be able
to detect some change. So, you need to focus your observations on a particular spot in the sky and always come back to that one point over head (adjusted for time of day and day of the year) .
Now all other stars are farther away from us than that one. So,
light reaching us from them has been traveling longer than 4.3
years to get here. Some stars are in the millions of light years from the Sun. And, yes, that light has been traveling for a million years or so to get here. So what you see is fairly old news, but highly interesting.
Go to http://www.space.com for some real neat photos of stars exploding.
Another interesting site is:
http:// curious.astro.cornell.edu/index.php
And I highly recommend Ian Ridpath's book "ASTRONOMY", DK Publishing, NY, NY, for more information on the subject.
2007-01-28 21:17:25 · answer #3 · answered by zahbudar 6 · 1⤊ 0⤋
Yes, we're looking in to the past.
Ones in other galaxies, that we see through big telescopes could have blown up millions of years ago and we'd never know about it.
When the light from the explosion reached us we'd know but the real star would have been long gone by then.
2007-01-28 20:30:15 · answer #4 · answered by Anonymous · 0⤊ 0⤋
It is possible they have imploded. Depending on how many light years they are away, a star could have imploded yet we would still see it from earth for nearly a thousand more years! For example, if Alpha Proximi, the closest star to earth exept for our sun, imploded, we would still see it for 4 more years, as it is four light years away. Make sense?
2007-01-28 20:12:30 · answer #5 · answered by Anonymous · 0⤊ 0⤋