Thursday, 26 November 2015

Stephan's Quintet


My image of Stephan's Quintet- Interacting galaxies some 290 million light years away- image taken using the Bradford Robotic Telescope.
 Some 290 million light years away these galaxies of trillions of stars are locked in a dance orchestrated by gravity. A celestial 'Lobster Quadrille' amongst the constellation of stars us earthlings have named Pegasus.

"Will you walk a little faster?" said a whiting to a snail,
"There's a porpoise close behind us, and he's treading on my tail.
See how eagerly the lobsters and the turtles all advance!
They are waiting on the shingle – will you come and join the dance?
Will you, won't you, will you, won't you, will you join the dance?
Will you, won't you, will you, won't you, won't you join the dance?
"You can really have no notion how delightful it will be
When they take us up and throw us, with the lobsters, out to sea!"
But the snail replied "Too far, too far!" and gave a look askance --
Said he thanked the whiting kindly, but he would not join the dance.
Would not, could not, would not, could not, would not join the dance.
Would not, could not, would not, could not, could not join the dance.
"What matters it how far we go?" his scaly friend replied.
"There is another shore, you know, upon the other side.
The further off from England the nearer is to France --
Then turn not pale, beloved snail, but come and join the dance.
Will you, won't you, will you, won't you, will you join the dance?
Will you, won't you, will you, won't you, won't you join the dance?
 
My image annotated to identify each separate galaxy

Galactic Wreckage in Stephan's Quintet. A clash among members of a famous galaxy quintet reveals an assortment of stars across a wide color range, from young, blue stars to ageing, red stars. This portrait of Stephan's Quintet, also known as Hickson Compact Group 92, was taken by the Wide Field Camera 3 (WFC3) aboard NASA's Hubble Space Telescope. Stephan's Quintet, as the name implies, is a group of five galaxies. The name, however, is a bit of a misnomer. Studies have shown that group member NGC 7320, at lower left, is actually a foreground galaxy about seven times closer to Earth than the rest of the group. Three of the galaxies have distorted shapes, elongated spiral arms, and long, gaseous tidal tails containing myriad star clusters, proof of their close encounters. These interactions have sparked a frenzy of star birth in the central pair of galaxies. This drama is being played out against a rich backdrop of faraway galaxies. The image, taken in visible and near-infrared light, showcases WFC3's broad wavelength range. The colors trace the ages of the stellar populations, showing that star birth occurred at different epochs, stretching over hundreds of millions of years. The camera's infrared vision also peers through curtains of dust to see groupings of stars that cannot be seen in visible light. NGC 7319, at top left, is a barred spiral with distinct spiral arms that follow nearly 180 degrees back to the bar. The blue specks in the spiral arm at the top of NGC 7319 and the red dots just above and to the right of the core are clusters of many thousands of stars. Most of the quintet is too far away even for Hubble to resolve individual stars. Continuing clockwise, the next galaxy appears to have two cores, but it is actually two galaxies, NGC 7318A and NGC 7318B. Encircling the galaxies are young, bright blue star clusters and pinkish clouds of glowing hydrogen where infant stars are being born. These stars are less than 10 million years old and have not yet blown away their natal cloud. Far away from the galaxies,  is a patch of intergalactic space where many star clusters are forming. NGC 7317, at bottom right, is a normal-looking elliptical galaxy that is less affected by the interactions. Sharply contrasting with these galaxies is the dwarf galaxy NGC 7320 at lower left. Bursts of star formation are occurring in the galaxy's disk, as seen by the blue and pink dots. In this galaxy, Hubble can resolve individual stars, evidence that NGC 7320 is closer to Earth. NGC 7320 is 40 million light-years from Earth. The other members of the quintet reside 290 million light-years away in the constellation Pegasus. These farther members are markedly redder than the foreground galaxy, suggesting that older stars reside in their cores. The stars' light also may be further reddened by dust stirred up in the encounters. Spied by Edouard M. Stephan in 1877, Stephan's Quintet is the first compact group ever discovered. WFC3 observed the quintet in July and August 2009. The composite image was made by using filters that isolate light from the blue, green, and infrared portions of the spectrum, as well as emission from ionized hydrogen. These Hubble observations are part of the Hubble Servicing Mission 4 Early Release Observations. NASA astronauts installed the WFC3 camera during a servicing mission  to upgrade and repair the 19-year-old Hubble telescope.

Credits: Wikipedia, "Stephan's Quintet Hubble 2009.full denoise" by NASA, ESA, and the Hubble SM4 ERO Team - http://www.hubblesite.org/newscenter/archive/releases/2009/25/image/x/ (direct link). Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Stephan%27s_Quintet_Hubble_2009.full_denoise.jpg#/media/File:Stephan%27s_Quintet_Hubble_2009.full_denoise.jpg

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