| T O P I C R E V I E W |
| Newo |
Posted - 03/27/2006 : 15:04:21
Astronomers report an unprecedented elongated double helix nebula near the center of our Milky Way galaxy, using observations from NASA's Spitzer Space Telescope. The part of the nebula the astronomers observed stretches 80 light years in length. The research is published March 16 in the journal Nature.
"We see two intertwining strands wrapped around each other as in a DNA molecule," said Mark Morris, a UCLA professor of physics and astronomy, and lead author. "Nobody has ever seen anything like that before in the cosmic realm. Most nebulae are either spiral galaxies full of stars or formless amorphous conglomerations of dust and gas — space weather. What we see indicates a high degree of order."
The double helix nebula is approximately 300 light years from the enormous black hole at the center of the Milky Way. (The Earth is more than 25,000 light years from the black hole at the galactic center.)
The Spitzer Space Telescope, an infrared telescope, is imaging the sky at unprecedented sensitivity and resolution; Spitzer's sensitivity and spatial resolution were required to see the double helix nebula clearly.
"We know the galactic center has a strong magnetic field that is highly ordered and that the magnetic field lines are oriented perpendicular to the plane of the galaxy," Morris said. "If you take these magnetic field lines and twist them at their base, that sends what is called a torsional wave up the magnetic field lines.
"You can regard these magnetic field lines as akin to a taut rubber band," Morris added. "If you twist one end, the twist will travel up the rubber band."
Offering another analogy, he said the wave is like what you see if you take a long loose rope attached at its far end, throw a loop, and watch the loop travel down the rope.
"That's what is being sent down the magnetic field lines of our galaxy," Morris said. "We see this twisting torsional wave propagating out. We don't see it move because it takes 100,000 years to move from where we think it was launched to where we now see it, but it's moving fast — about 1,000 kilometers per second — because the magnetic field is so strong at the galactic center — about 1,000 times stronger than where we are in the galaxy's suburbs."
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Gravy boat! Stay in the now! |
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| Carl |
Posted - 03/27/2006 : 17:32:14
I'm clueless about astronomical matters (although I do have an interest), but it does sound important if that shape of nebula hasn't been seen before.
 pas de dutchie! |
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