APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Comments and questions about the APOD on the main view screen.

APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby APOD Robot » Sun Jul 11, 2010 4:03 am

Image Warped Sky: Star Trails Panorama

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 four 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 South Celestial Pole, on the left, and the North Celestial Pole, just below the horizon on the right. The image captured the sky over Mudgee, New South Wales, Australia, including the domes of two large telescopes illuminated by red lighting. A horizontally unwarped image is visible by clicking on the image. Total Solar Eclipse Today: Times and Visibility | Webcast

<< Previous APODDiscuss Any APOD Next APOD >>
User avatar
APOD Robot
Otto Posterman
 
Posts: 1711
Joined: Fri Dec 04, 2009 3:27 am

The whorl according to Warp.

Postby neufer » Sun Jul 11, 2010 5:10 am

    -----------------------------------------------
    . They heard, and up they sprung upon the wing
    . Innumerable. As when the potent rod
    . Of Amram's son, in Egypt's evil day,
    . Waved round the coast, up call'd a pitchy cloud
    . Of locusts, warping on the eastern wind
    . That o'er the realm of impious Pharaoh hung
    . Like night, and darken'd all the realm of Nile,
    . So numberless were they.
    - Paradise Lost.
    -----------------------------------------------
    ___ As You Like It Act 3, Scene 3

    JAQUES: And will you, being a man of your breeding, be
    ___ married under a bush like a beggar? Get you to
    ___ church, and have a good priest that can tell you
    ___ what marriage is: this fellow will but join you
    ___ together as they join wainscot; then one of you will
    ___ prove a shrunk panel and, like green timber, warp, warp.
    -----------------------------------------------
Warp, v. i. [OE. warpen; fr. Icel. varpa to throw, cast, varp a casting, fr. verpa to throw; akin to
. Dan. varpe to warp a ship, Sw. varpa, AS. weorpan to cast; cf. Skr. vrj to twist. Cf. Wrap.]

1. To turn, twist, or be twisted out of shape; esp., to be twisted or bent out of a flat plane.

2. to turn or incline from a straight, true, or proper course; to deviate; to swerve.

3. To fly with a bending or waving motion; to turn and wave, like a flock of birds or insects.
-----------------------------------------------
Warp, n. [AS. wearp; akin to Icel. varp a casting, throwing,
. Sw. varp the draught of a net, Dan. varp a towline, OHG. warf warp, G. werft.]

1. (Weaving) The threads which are extended lengthwise in the loom, and crossed by the woof.

3. (Agric.) A slimy substance deposited on land by tides,

6. [From Warp, v.] The state of being warped or twisted; as, the warp of a board.
. Warp beam, the roller on which the warp is wound in a loom.
-----------------------------------------------
http://en.wikipedia.org/wiki/Time_warp_ ... fiction%29 wrote:
<<The terms time warp, space warp and time-space warp are commonly used in science non-fiction. They sometimes refer to Einstein's theory that time and space form a continuum which bends, folds or warps from the observer's point of view, relative to such factors as movement or gravitation, but are also used in reference to more fantastic notions of discontinuities or other irregularities in spacetime not based on real-world science. In science fiction, "warp drive" is often a name given to travel faster than the speed of light. Notably in the Star Trek television series Warp Factor is a name given to the number of times faster than light the fictional spacecraft has effectively moved.>>
------------------------------------
http://en.wikipedia.org/wiki/Dynamic_time_warping wrote:
<<Dynamic time warping is an algorithm for measuring similarity between two sequences which may vary in time or speed. For instance, similarities in walking patterns would be detected, even if in one video the person was walking slowly and if in another he or she were walking more quickly, or even if there were accelerations and decelerations during the course of one observation. A well known application has been automatic speech recognition, to cope with different speaking speeds.

In general, DTW is a method that allows a computer to find an optimal match between two given sequences (e.g. time series) with certain restrictions. The sequences are "warped" non-linearly in the time dimension to determine a measure of their similarity independent of certain non-linear variations in the time dimension. This sequence alignment method is often used in the context of hidden Markov models. DTW is an algorithm particularly suited to matching sequences with missing information, provided there are long enough segments for matching to occur.

The extension of the problem for two-dimensional "series" like images (planar warping) is NP-complete,
while the problem for one-dimensional signals like time series can be solved in polynomial time.>>
------------------------------------
Art Neuendorffer
User avatar
neufer
Abstruse Allusion Artificer
 
Posts: 11394
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby orin stepanek » Sun Jul 11, 2010 12:29 pm

An interesting picture; though not a favorite. :shock:
Orin

Smile today; tomorrow's another day!
User avatar
orin stepanek
Plutopian
 
Posts: 4174
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby neufer » Sun Jul 11, 2010 1:28 pm

orin stepanek wrote:An interesting picture; though not a favorite. :shock:

      It's a Wonderful Life (1946)
    Potter: Look at you. You used to be so cocky. You were going to go out and conquer the world. You once called me "a warped, frustrated, old man!" What are you but a warped, frustrated young man? A miserable little clerk crawling in here on your hands and knees and begging for help. No securities, no stocks, no bonds. Nothin' but a miserable little $500 equity in a life insurance policy.
Art Neuendorffer
User avatar
neufer
Abstruse Allusion Artificer
 
Posts: 11394
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby Redbone » Sun Jul 11, 2010 1:54 pm

The original has a resolution of 1877 x 400. The compressed is 900 x 600. I hope that most folks are using a monitor with greater than 900 x 600 resolution. If not then you owe it to yourself to get a new monitor.
User avatar
Redbone
Ensign
 
Posts: 78
Joined: Tue Oct 09, 2007 11:14 am
Location: Frederick Maryland, USA

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby owlice » Sun Jul 11, 2010 2:13 pm

I'm wondering what the reddish streak from ground to sky on the right side of the image is.
A closed mouth gathers no foot.
User avatar
owlice
Guardian of the Codes
 
Posts: 7872
Joined: Wed Aug 04, 2004 4:18 pm
Location: Washington, DC

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby bystander » Sun Jul 11, 2010 2:56 pm

owlice wrote:I'm wondering what the reddish streak from ground to sky on the right side of the image is.

If it was over one of the observatories, I would have thought it one of those laser guides they use to correct for atmospheric distortion, but in the full resolution, it is curved, although that may be an image artifact. I'm thinking the flattening of the southern star trails at the top of the picture is an artifact, too.

orin stepanek wrote:An interesting picture; though not a favorite. :shock:

I'm with Orin on this. I'm just not that enamored with star trails, except those of the galactic kind. The different stellar colors are interesting, though.
User avatar
bystander
Apathetic Retiree
 
Posts: 11941
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby owlice » Sun Jul 11, 2010 3:50 pm

Wow, bystander, thanks for the link; that's a great (and instructive!) image!

I think there is utility in star trail images, both for the stellar colors and for demonstration of the earth's rotation. And some are quite pretty. This one is interesting to me because it shows (nearly) both poles.

I wish I'd thought of this sooner (as in, oh, about eight years ago!), but showing a kid how to take such images might be a good way to pique an interest in the night sky.
A closed mouth gathers no foot.
User avatar
owlice
Guardian of the Codes
 
Posts: 7872
Joined: Wed Aug 04, 2004 4:18 pm
Location: Washington, DC

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby WillyD » Sun Jul 11, 2010 5:58 pm

Looks like something Vincent would paint.
WillyD
 

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby orin stepanek » Sun Jul 11, 2010 8:10 pm

bystander wrote:
orin stepanek wrote:An interesting picture; though not a favorite. :shock:

I'm with Orin on this. I'm just not that enamored with star trails, except those of the galactic kind. The different stellar colors are interesting, though.

Thanks bystander! Now that's the kind of picture I like. I guess star trails are OK; if you like them. I appreciate the work that photographers do to make them; but they just don't move me. I do sometimes like the Earthly foreground on some of them though.
Orin

Smile today; tomorrow's another day!
User avatar
orin stepanek
Plutopian
 
Posts: 4174
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby moonstruck » Sun Jul 11, 2010 8:31 pm

Interesting picture. I suppose if the photographer was standing at 0 degree latitude both pole's would be equally above the horizon. Huh? Well... not standing, but on a tripod. :?
moonstruck
Science Officer
 
Posts: 164
Joined: Fri Jun 18, 2010 2:27 pm

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby Ann » Sun Jul 11, 2010 9:11 pm

Great galaxy picture, Bystander!

And today's APOD is nice enough because there are two apparent centers of the star trails. Ordinarily, though, I'm not a fan of star trail pictures. It frankly drives me nuts that I can't identify the stars!

Ann
Color Commentator
User avatar
Ann
4725 Å
 
Posts: 5400
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby neufer » Sun Jul 11, 2010 10:34 pm

Ann wrote:And today's APOD is nice enough because there are two apparent centers of the star trails. Ordinarily, though, I'm not a fan of star trail pictures. It frankly drives me nuts that I can't identify the stars!

Then you probably aren't trying very hard. :)
Art Neuendorffer
User avatar
neufer
Abstruse Allusion Artificer
 
Posts: 11394
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby DavidLeodis » Mon Jul 12, 2010 2:29 pm

owlice wrote:I'm wondering what the reddish streak from ground to sky on the right side of the image is.


Hi owlice. In the image description brought up through the 'This image' link it states "The near vertical red arcs at the centre and far left of the image are the navigation lights of a passing jet aircraft". They are seen better in the uncompressed image.
User avatar
DavidLeodis
A Tiger Named Lion
 
Posts: 720
Joined: Mon May 01, 2006 1:00 pm

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby owlice » Mon Jul 12, 2010 2:38 pm

David, I'd missed that! Thank you!!
A closed mouth gathers no foot.
User avatar
owlice
Guardian of the Codes
 
Posts: 7872
Joined: Wed Aug 04, 2004 4:18 pm
Location: Washington, DC

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby biddie67 » Mon Jul 12, 2010 8:48 pm

warped -or- non-warped, I'm confused as to how a location so far south in the southern hemisphere can still see part of the star trails around the northern celestrial pole ??????
biddie67
Science Officer
 
Posts: 483
Joined: Sun Jan 31, 2010 9:44 am
Location: Possum Hollow, NW Florida

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby DavidLeodis » Mon Jul 12, 2010 9:04 pm

owlice wrote:David, I'd missed that! Thank you!!


I've just realised that I have been a bit slow in regards to "The near vertical red arcs at the centre and far left of the image are the navigation lights of a passing jet aircraft". I cannot readily discern those red arcs in the image but that on the far right is very obvious, so I wonder if at least that said to be in the far left is a mistake and should say far right (or perhaps I need better eye sight!). :) :oops:
User avatar
DavidLeodis
A Tiger Named Lion
 
Posts: 720
Joined: Mon May 01, 2006 1:00 pm

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby Chris Peterson » Mon Jul 12, 2010 9:09 pm

biddie67 wrote:warped -or- non-warped, I'm confused as to how a location so far south in the southern hemisphere can still see part of the star trails around the northern celestrial pole ??????

From the location of the observatory (latitude 33°S) it is possible to see stars from declination -90° to declination +57°. That means that about 2/3 of the northern stars are visible, which looks pretty much like what the image is showing.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
User avatar
Chris Peterson
Abominable Snowman
 
Posts: 8730
Joined: Wed Jan 31, 2007 11:13 pm
Location: Colorado, USA

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby neufer » Mon Jul 12, 2010 10:20 pm

DavidLeodis wrote:
I've just realised that I have been a bit slow in regards to "The near vertical red arcs at the centre and far left of the image are the navigation lights of a passing jet aircraft". I cannot readily discern those red arcs in the image but that on the far right is very obvious, so I wonder if at least that said to be in the far left is a mistake and should say far right (or perhaps I need better eye sight!). :) :oops:

Since the image was taken in the Southern Hemisphere you must stand on your head to observe it properly...thus making the red arc on the far left.
Art Neuendorffer
User avatar
neufer
Abstruse Allusion Artificer
 
Posts: 11394
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby bystander » Mon Jul 12, 2010 10:29 pm

There are actually three red arcs, on the left, center, and right. The one on the left is a continuation of the one on the right (top third of the frame). The one in the center is just right of the left observatory.
User avatar
bystander
Apathetic Retiree
 
Posts: 11941
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby biddie67 » Mon Jul 12, 2010 11:27 pm

Chris Peterson wrote: ]
From the location of the observatory (latitude 33°S) it is possible to see stars from declination -90° to declination +57°. That means that about 2/3 of the northern stars are visible, which looks pretty much like what the image is showing.


Thanks, Chris for pointing out the -90° sweep which allows the stars up to about latitude +57° to be seen. By coincidence, I am located at about 35° N and I was very much aware of the circumpolar path of the stars around Polaris but it never occurred to me to focus on circumpolar views to the south other than to locate Fomalhaut in the winter ......
biddie67
Science Officer
 
Posts: 483
Joined: Sun Jan 31, 2010 9:44 am
Location: Possum Hollow, NW Florida

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby DavidLeodis » Tue Jul 13, 2010 11:10 am

neufer wrote:
DavidLeodis wrote:
I've just realised that I have been a bit slow in regards to "The near vertical red arcs at the centre and far left of the image are the navigation lights of a passing jet aircraft". I cannot readily discern those red arcs in the image but that on the far right is very obvious, so I wonder if at least that said to be in the far left is a mistake and should say far right (or perhaps I need better eye sight!). :) :oops:

Since the image was taken in the Southern Hemisphere you must stand on your head to observe it properly...thus making the red arc on the far left.


Nice try neufer. :lol: Not that I could stand on my head now, but it was fun when I was a child. :)
User avatar
DavidLeodis
A Tiger Named Lion
 
Posts: 720
Joined: Mon May 01, 2006 1:00 pm

Re: APOD: Warped Sky: Star Trails Panorama (2010 Jul 11)

Postby DavidLeodis » Tue Jul 13, 2010 11:19 am

bystander wrote:There are actually three red arcs, on the left, center, and right. The one on the left is a continuation of the one on the right (top third of the frame). The one in the center is just right of the left observatory.


Thanks bystander. :). It's odd that the explanation feels need to note the left and center arcs which are not at all obvious in the image yet there is no mention of the obvious red streak in the right!
User avatar
DavidLeodis
A Tiger Named Lion
 
Posts: 720
Joined: Mon May 01, 2006 1:00 pm


Return to The Bridge: Discuss an Astronomy Picture of the Day

Who is online

Users browsing this forum: Baidu [Spider], CommonCrawl [Bot], Facebook [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] and 10 guests