Now here's an interesting news item:
Milky Way stars move in mysterious ways
Quote:
Rather than moving in circles around the center of the Milky Way, all the stars in our Galaxy are travelling along different paths, moving away from the Galactic center.
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This strange behavior may be due to perturbation caused by the central bar and spiral arms of our Galaxy, forcing stars to leave their normal circular course and take an outward path.
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For over twenty years, scientists believed that the potential impact of these density waves on stellar velocities in the Milky Way was insignificant in comparison with the circular motion of the stars in the galactic disk. This belief has now been blatantly proved wrong by an international team
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To reach this conclusion, the team systematically analyzed the velocities of over two hundred thousand stars located within a radius of a little over six thousand light years around the Sun. Using data from the major star survey RAVE (RAdial Velocity Experiment) collected since 2003 by the Australian Astronomical Observatory's Schmidt telescope, they were able to measure for the first time the radial velocities of hundreds of thousands of stars and determine whether they were moving towards or away from us.
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The researchers were thus able to ascertain that the average speed of stars towards the exterior of the Galaxy increases with their distance from the Sun in the direction of the Galactic center
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The RAVE website and papers are
here
This stellar motion stuff just gets more and more perplexing !
They're saying that the combined effect of the central bar and the spiral arms could explain the motion (as close as 6K lyrs from the Sun) !! Fascinating !! More reading to do on this one !!
Cheers