Night sky with supernova, black holes closer.

[cosmicalstorm]

Our night-sky if some major astronomic objects were a lot closer.
https://www.youtube.com/watch?v=JXozLX1ufVE

[Iroscato]

Man I love videos like these, they're so awesome and trippy.
Have another

[Simon_Jester]

I wonder how they determine which objects are bright enough to be seen in daylight or relative to a brightly lit night scene- I mean, having a cluster of a hundred thousand stars at a distance of, oh, a thousand light years (as portrayed at around 1:30) would be all manner of impressive but I don't know if you'd be able to see it in the evening sky if the individual stars weren't bright enough to be seen anyway.

Also, the supernova remnants are shown so close up that if we could see them that well they'd have killed us. O_o

[Iroscato]

I wonder how they determine which objects are bright enough to be seen in daylight or relative to a brightly lit night scene- I mean, having a cluster of a hundred thousand stars at a distance of, oh, a thousand light years (as portrayed at around 1:30) would be all manner of impressive but I don't know if you'd be able to see it in the evening sky if the individual stars weren't bright enough to be seen anyway.

Also, the supernova remnants are shown so close up that if we could see them that well they'd have killed us. O_o

Sssshh...just enjoy the pretty images

[Eternal_Freedom]

I wonder how they determine which objects are bright enough to be seen in daylight or relative to a brightly lit night scene- I mean, having a cluster of a hundred thousand stars at a distance of, oh, a thousand light years (as portrayed at around 1:30) would be all manner of impressive but I don't know if you'd be able to see it in the evening sky if the individual stars weren't bright enough to be seen anyway.

Also, the supernova remnants are shown so close up that if we could see them that well they'd have killed us. O_o

There is a formula called the distance modulus relating relative and absolute magnitude and distance. Relative magnitude is how they appear from Earth, a magnitude of 5-6 is the faintest you'll see with naked eyes. Absolute magnitude is how bright they woudl appear from 10 parsecs/33 light-years away.

So if we know the absolute magnitude (which we can derive from how bright they appear and how far away they are) we can place them at an arbitrary distance and see how bright they would appear.

As for the stars not being bright enough to be seen, well, stars in other galaxies aren't bright enough to be seen (except supernovas) but we still see the cumulative light from the galaxy.

[Simon_Jester]

Eh, what I meant to say was more like "I'm not sure they did the math right." Also, cumulative light from a large cloud of stars would show up really poorly against the daytime sky because it'd just be a slightly brighter patch of sky. I doubt the eye would be able to sort out the starlight from the background. A nebula might be different or might not, depending on details.

[cosmicalstorm]

I think there is some cheating too. The night-sky if these impressive objects were closer, had not fried us, and your eyes were replaced with high-power bionic eyes.

Can't find any decent animation done on what the sky would look like when hit by a GRB or an RKV.

[Eternal_Freedom]

Eh, what I meant to say was more like "I'm not sure they did the math right." Also, cumulative light from a large cloud of stars would show up really poorly against the daytime sky because it'd just be a slightly brighter patch of sky. I doubt the eye would be able to sort out the starlight from the background. A nebula might be different or might not, depending on details.

Ah I see. I'd have to crunch the numbers to see how bright and how big things would be and frankly I'm not quite bored enough to do that.

I think you are right that even a large globular cluster at ~1000 ly wouldn't really be seen in daytime. Nighttime, most definitely, even for light-polluted areas.

As for a night sky being hit by a GRB or RKV, well, an RKV would look like a very fast asteroid strike I would think. A GRB, hmm, if we're not too close to be fried by it we would probably see a very bright blue flash of Cerenkov radiation like we do with normal high-energy cosmic rays, just on a massive scale.