See new, spectacular, or mysterious sky images.
-
bystander
- Apathetic Retiree
- Posts: 21590
- Joined: Mon Aug 28, 2006 2:06 pm
- Location: Oklahoma
Post
by bystander » Mon Sep 06, 2010 4:56 pm
An Extraordinary Celestial Spiral
Hubble European Picture of the Week | potw1020a | 06 Sept 2010
This remarkable picture from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope shows one of the most perfect geometrical forms created in space. It captures the formation of an unusual pre-planetary nebula, known as IRAS 23166+1655, around the star LL Pegasi (also known as AFGL 3068) in the constellation of Pegasus (the Winged Horse).
The striking picture shows what appears to be a thin spiral pattern of astonishingly regularity winding around the star, which is itself hidden behind thick dust. The spiral pattern suggests a regular periodic origin for the nebula’s shape. The material forming the spiral is moving outwards a speed of about 50 000 km/hour and, by combining this speed with the distance between layers, astronomers calculate that the shells are each separated by about 800 years.
The spiral is thought to arise because LL Pegasi is a binary system, with the star that is losing material and a companion star orbiting each other. The spacing between layers in the spiral is expected to directly reflect the orbital period of the binary, which is indeed estimated to be also about 800 years.
The creation and shaping of planetary nebulae is an exciting area of stellar evolution. Stars with masses from about half that of the Sun up to about eight times that of the Sun do not explode as supernovae at the ends of their lives. Instead a more regal end awaits them as their outer layers of gas are shed and drift into space, creating striking and intricate structures that to Earth-bound observers often look like dramatic watercolour paintings. IRAS 23166+1655 is just starting this process and the central star has yet to emerge from the cocoon of enveloping dust.
This picture was created from images from the Wide Field Channel of the Advanced Camera for Surveys on Hubble. Images through a yellow filter (F606W, coloured blue) were combined with images through a near-infra red filter (F804W, coloured red). The exposure times were 11 minutes and 22 minutes respectively and the field of view spans about 80 arcseconds.
Credit: NASA/ESA/R. Sahai
A Binary-Induced Pinwheel Outflow from the Extreme Carbon Star, AFGL 3068 - M Morris
et al
Awesome death spiral of a bizarre star
Discover Blogs | Bad Astronomy | 06 Sept 2010
-
x00x
- Ensign
- Posts: 15
- Joined: Wed Jul 27, 2005 7:31 am
Post
by x00x » Tue Sep 07, 2010 5:35 am
This remarkable picture from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope shows one of the most perfect geometrical forms created in space.
Still, as beautiful and compelling as this celestial spiral is, the bizarre,inexplicable hexagon on Saturn's North Pole remains my number one most perfect geometric form created in space. Everything about it is so absolutely freaking awesome. Saturn's hexagon is the very first destination on my top ten favorite places to see, visit in our solar system, once, of course, we develop warp drive.
-
neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Post
by neufer » Tue Sep 07, 2010 5:01 pm
http://en.wikipedia.org/wiki/Archimedean_spiral wrote:
<<The Archimedean spiral (also known as the arithmetic spiral) is the locus of points corresponding to the locations over time of a point moving away from a fixed point with a constant speed along a line which rotates with constant angular velocity. One method of squaring the circle, by relaxing the strict limitations on the use of straightedge and compass in ancient Greek geometric proofs, makes use of an Archimedean spiral. Virtually all static spirals appearing in nature are logarithmic spirals, not Archimedean ones. Many dynamic spirals (such as the Parker spiral of the solar wind, or the pattern made by a
Catherine's wheel) are Archimedean.
The Archimedean spiral has a plethora of real-world applications. Scroll compressors, made from two interleaved Archimedean spirals of the same size, are used for compressing liquids and gases. The coils of watch balance springs and the grooves of very early gramophone records form Archimedean spirals, making the grooves evenly spaced and maximizing the amount of music that could be fit onto the record (although this was later changed to allow better sound quality).[2] Asking for a patient to draw an Archimedean spiral is a way of quantifying human tremor; this information helps in diagnosing neurological diseases. Archimedean spirals are also used in DLP projection systems to minimize the "Rainbow effect", making it look as if multiple colors are displayed at the same time, when in reality red, green, and blue are being cycled extremely quickly. Also, Archimedean spirals are used in food microbiology to quantify bacterial concentration through a spiral platter.>>
Art Neuendorffer
-
geckzilla
- Ocular Digitator
- Posts: 9180
- Joined: Wed Sep 12, 2007 12:42 pm
- Location: Modesto, CA
-
Contact:
Post
by geckzilla » Wed Sep 08, 2010 12:52 am
How could I have never heard about this structure before? Seeing the picture and not reading the description I thought it was going to be another test missile in Earth's atmosphere again.
Just call me "geck" because "zilla" is like a last name.
-
neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Post
by neufer » Wed Sep 08, 2010 3:15 am
geckzilla wrote:How could I have never heard about this structure before?
Because it was just discovered?
http://www.universetoday.com/73034/hubble-spies-an-amazing-cosmic-spiral/ wrote:
Hubble Spies an Amazing Cosmic Spiral
Posted in: Astronomy, Hubble by Nancy Atkinson (22 Comments »)
<<A progression of quasi-concentric shells has been observed around a number of preplanetary nebulae, but this almost perfect spiral shape is unique.
Morris and his team say that the structure of the AFGL 3068 envelope raises the possibility that binary companions are responsible for quasi-concentric shells in most or all of the systems in which they have been observed, and the lack of symmetry in the shells seen elsewhere can perhaps be attributed to orbital eccentricity,
to different projections of the orbital planes, and to unfavorable illumination geometries.
Additionally – and remarkably — this object may be illuminated by galactic light.>>
Art Neuendorffer
-
geckzilla
- Ocular Digitator
- Posts: 9180
- Joined: Wed Sep 12, 2007 12:42 pm
- Location: Modesto, CA
-
Contact:
Post
by geckzilla » Wed Sep 08, 2010 10:48 am
Oh, I thought I was just living under a rock.
Just call me "geck" because "zilla" is like a last name.
-
neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Post
by neufer » Wed Sep 08, 2010 11:52 am
geckzilla wrote:Oh, I thought I was just living under a rock.
Well...that too.
![Image](http://www.geckostone.com/Images/y2gecko9.jpg)
Art Neuendorffer