APOD: Warped Sky: Star Trails over Arches... (2014 Mar 17)

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APOD: Warped Sky: Star Trails over Arches... (2014 Mar 17)

Post by APOD Robot » Mon Mar 17, 2014 4:05 am

Image Warped Sky: Star Trails over Arches National Park

Explanation: What's happened to the sky? A time warp, of sorts, and a digital space warp too. The time warp occurs because this image captured in a single frame a two and a half hour exposure of the night sky. As a result, prominent star trails are visible. The space warp occurs because the picture is actually a full 360 degree panorama, horizontally compressed to fit your browser. As the Earth rotated, stars appeared to circle both the North Celestial Pole, on the left, and the South Celestial Pole, just below the horizon on the right. The above panorama over Arches National Park in Utah, USA, was captured two weeks ago during early morning hours. While the eye-catching texture of ancient layered sandstone covers the image foreground, twenty-meter tall Delicate Arch is visible on the far right, and the distant arch of our Milky Way Galaxy is visible near the image center.

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Case » Mon Mar 17, 2014 5:50 am

APOD Robot wrote:As a result, prominent star trails are visible.
What an unusual way to display star trails! :D
It seems each star starts as a clearly visible point in the sky and then fades out over the duration of total exposure time.
Lovely different from other star trail images.

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Nitpicker » Mon Mar 17, 2014 5:58 am

Case wrote:
APOD Robot wrote:As a result, prominent star trails are visible.
What an unusual way to display star trails! :D
It seems each star starts as a clearly visible point in the sky and then fades out over the duration of total exposure time.
Lovely different from other star trail images.
I think each star trail is ending with a more prominent point. Looks like the focus was tweaked a little at the end. Can also see the Milky Way rising in the East.

Not sure what caused the few wobbles in the trails ... possibly a stitching line, so as to split at a more aesthetic point? Seems to be a bit shy of 360&deg;, too, but still very interesting.

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Ann » Mon Mar 17, 2014 6:22 am

Stellar fireworks! Nice! :D

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Nitpicker » Mon Mar 17, 2014 6:36 am

Nitpicker wrote:Not sure what caused the few wobbles in the trails ... possibly a stitching line, so as to split at a more aesthetic point? Seems to be a bit shy of 360&deg;, too, but still very interesting.
Oops, just read that this image was composed from many sub-exposures using 4 cameras operating concurrently, pointing in different directions. I misread the caption's "this image captured in a single frame" as though it was a single exposure from a single camera.

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Boomer12k » Mon Mar 17, 2014 9:07 am

Looks like "A Starry Night" by Van Gogh. All those swirls.

Awesome!!!

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by orin stepanek » Mon Mar 17, 2014 11:32 am

OH my! :o
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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by CURRAHEE CHRIS » Mon Mar 17, 2014 1:08 pm

Nitpicker wrote:
Nitpicker wrote:Not sure what caused the few wobbles in the trails ... possibly a stitching line, so as to split at a more aesthetic point? Seems to be a bit shy of 360&deg;, too, but still very interesting.
Oops, just read that this image was composed from many sub-exposures using 4 cameras operating concurrently, pointing in different directions. I misread the caption's "this image captured in a single frame" as though it was a single exposure from a single camera.
I did the same thing :)

Really interesting picture!!

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Ron-Astro Pharmacist » Mon Mar 17, 2014 2:31 pm

The star trails have a similar appearance to field lines.
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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Psnarf » Mon Mar 17, 2014 2:55 pm

Polaris appears stationary. Is that because of the short exposure time? Longer such exposures show Polaris circling a point above Earth's rotational axis. Perhaps the 13Kyr precession has put Polaris back in its place above our Celestial North Pole?

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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Chris Peterson » Mon Mar 17, 2014 3:34 pm

Psnarf wrote:Polaris appears stationary. Is that because of the short exposure time? Longer such exposures show Polaris circling a point above Earth's rotational axis. Perhaps the 13Kyr precession has put Polaris back in its place above our Celestial North Pole?
Polaris is 0.7° from the pole, so it definitely is seen to rotate. But the wider the field, the less apparent the rotation. And in this image, the rotation is going to manifest mainly as an elongation (which I believe we can see, although the geometric aberrations may mask it), and even that is partly hid by exposure saturation.
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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by Anthony Barreiro » Mon Mar 17, 2014 8:35 pm

Who needs LSD when we have PhotoShop?
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Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1

Post by LocalColor » Mon Mar 17, 2014 10:52 pm

Lovely presentation (and a lot of work stitching it together!) At Mr. Brady's site we really like the Devil's Tower photo - very "starry night-ish'.

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