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APOD: Warped Sky: Star Trails over Arches... (2014 Mar 17)
Posted: Mon Mar 17, 2014 4:05 am
by APOD Robot
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.
[/b]
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 5:50 am
by Case
APOD Robot wrote:As a result, prominent star trails are visible.
What an unusual way to display star trails!
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.
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 5:58 am
by Nitpicker
Case wrote:APOD Robot wrote:As a result, prominent star trails are visible.
What an unusual way to display star trails!
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°, too, but still very interesting.
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 6:22 am
by Ann
Stellar fireworks! Nice!
Ann
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 6:36 am
by Nitpicker
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°, 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.
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 9:07 am
by Boomer12k
Looks like "A Starry Night" by Van Gogh. All those swirls.
Awesome!!!
:---[===] *
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 11:32 am
by orin stepanek
OH my!
![Surprised :o](./images/smilies/icon_surprised.gif)
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 1:08 pm
by CURRAHEE CHRIS
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°, 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!!
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 2:31 pm
by Ron-Astro Pharmacist
The star trails have a similar appearance to field lines.
![Field Lines](./download/file.php?id=12712&sid=16e4c4ddd9bb167d86ac56d3bc50ef2e)
- Field Lines
- Field Lines.jpg (3.58 KiB) Viewed 2793 times
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 2:55 pm
by Psnarf
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?
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 3:34 pm
by Chris Peterson
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.
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 8:35 pm
by Anthony Barreiro
Who needs LSD when we have PhotoShop?
Re: APOD: Warped Sky: Star Trails over Arches... (2014 Mar 1
Posted: Mon Mar 17, 2014 10:52 pm
by LocalColor
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'.