Originally posted by azdude1804
i think ur wrong about the years there buddy. i think i might be getting a little confused. but if it was 425 lightyears away, then it would be, probably thousands of years before we saw it, because 1 lightyear equals 4 earth years. so what ever amount of lightyears u have, quadruple it in earth years.

No, one light year is the same one earth year. They both last one year. A light year is just a unit of measurment of how far light travels during one year.

Originally posted by ChrisRT

Thats not true, your thinking the wrong way round, it would just mean it actually happened 425 years ago and we can only see it starting to blow up now.

That is what I said. Also, it wouldn’t have the same luminance as our Moon...

Ok, after carefully re-reading your post, I believe you got your logic right after all, my mistake. I stand by my statement about the moon, obviously not as big though.

Gazrok, i was always inclined to think there was more 'control' behind that guiding star, but you could be equally right, good point.

Originally posted by azdude1804
i think ur wrong about the years there buddy. i think i might be getting a little confused. but if it was 425 lightyears away, then it would be, probably thousands of years before we saw it, because 1 lightyear equals 4 earth years. so what ever amount of lightyears u have, quadruple it in earth years.

Erm. No.

A lightyear is approximately 5,869,713,600,000 miles (5 trillion eight hundred sixty nine billion seven hundred thirteen million six hundred thousand miles), the distance that light travels (on average) during one earth year.

You can calculate this by taking
186,000 (miles per second, the speed of light)
times 60 (seconds in one minute)
times 60 (minutes in one hour)
times 24 (hours in one day)
times 365.25 (days in one year)

Technically, lightyear as a unit of measurement is frowned upon, but it's easy shorthand for newspaper articles. Saying a star is 425 lightyears away is a lot more digestable than saying it's 2,494,628,280,000,000 miles, or 3,991,405,248,000,000 km away

Originally posted by PanzerDiv
You have to take into account the pure distance! It might have already happened and we havent seen the light from the Supernova yet!

the person who discovered a star that is about to go supernova would have obseverved it at this great distance, so the distance is irrelevant. lets say they predict that it'll go supernova a year from now by observation. If its 2 million light years away it went supernova 1,999,999 years ago, but it will still happen for us a year from now.

``

that supernova you've all been referencing
was that the one in 1066 AD ???

if your really into it
there was a very close (in cosmic neighborhood) Nova
about 2 million years ago
in fact our whole solar system is in a molecular cloud 'tunnel'
or void area blasted out by that super-nova

maybe that GammaRayBurst from that super-Nova affected
our primitive ancestors.......for example the branch of Homo
of which the fossile named "Lucy" is about that old....

maybe the GRB mutated the DNA that eventually led to modern man?

(its difficult to favor one science [anthropology,astronomy] over another as a career choice...?eh)

Originally posted by PanzerDiv
I remember a documentry i watched that said if a supernova would occur within 25 lightyears of earth, That the earth would Fry!

The nearest star besides are own is 11 light years away from us (possibly nine?). I sure hope none of them go anytime soon.

Well it all depends on how far away it is If that one 4 light years away goes we might be in for a world of hurt 4 years after it happens.

Be lucky that you guyz wont be around when our life giving sun decideds to Nova! Of course earth would already be gone b/c of the Big red giant transformation!/
What is the limit on how close a supernova would be to destroy earth? 25 lightyears?