Recent comments in /f/space

Cosmo-Curious OP t1_j3gockt wrote

Camera - ASI533mm Pro Scope - GT71 Mount - HEQ5

17 hours of integration

Really happy with how this one came out compared to my previous attempts. I got the chance to shoot from under a bortle 4 sky compared to my usual 9.

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Riegel_Haribo OP t1_j3g27iu wrote

Going back to the nine-layer oversampled composition, here is 2048x2048 (double the source resolution) with no sharpening, but craters of the rotating moon aligned instead of the eclipse edge. https://i.imgur.com/trbuGZc.png

I tried an AI upsampler and it turned this into space junk. Titan's atmosphere IS blurry. https://i.imgur.com/xx3CJA1.png

I could put multiple high-res elements together to make a fake occultation, or even do a re-assembly of the transit in original moon colors, but I'm not a McCarthy. This is light right out of the telescope.

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whiskysinger t1_j3fzhrd wrote

Yes - it is exactly the same mechanism as the star trails taken from Earth's surface. Except the ISS is orbiting much quicker than the Earth is rotating. This is why the trails in this photo are so long for such a short exposure*.

Interestingly, the celestial pole is different on the iss than what we are used to on earth (Polaris in the northern hemisphere) because the orbital axis is not the same as Earth's axis of rotation, as demonstrated in the gif below.

https://gfycat.com/meagerscientificbengaltiger

*The ISS takes 90 minutes to orbit the earth. This means it is completing one trip around its orbital axis 16 times per earth day. The photo took 65 seconds of exposure. To capture star trails of this length on earth would take 16 x 65 seconds = 1040 seconds = 17m20s of exposure. (I think! Please correct me if I'm wrong)

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