14 DAY TRIAL // A strange thing happens at the very core of our galaxy. It seems that a spinning bar of material may be throwing nearby stars outwards as it rotates and most of them are heading towards our solar system. Fortunately, none of these stars has any chance of actually reaching us.
A team of researchers led by Thomas Bensby of the University of Michigan in Ann Arbor, US, have analyzed this phenomenon and hope it will shed some light on the distribution of dark matter in the Milky Way.
Faint streams of stars have been observed moving at the same speed in space and some of them are thought to be dwarf galaxies falling into the Milky Way and being stretched apart by the immense gravity of our galaxy.
Other streams may be ancient star clusters on the outskirts of our galaxy that are being ripped apart for the same reason. So it would seem that many of the stars coming from these clusters and dwarf galaxies may be expelled by this bar.
After analyzing 60 stars, especially the spectrum of each star, with the help of the 6.5-meter Magellan telescope in Chile, they found evidence of this slingshot effect that may affect stars in the Milky Way's disk.
"They show the same pattern known to exist in the galaxy," says team member Sally Oey, also of the University of Michigan. "There is no reason to believe that the star formation history in a different galaxy with completely different conditions should be similar to the star formation history in our galaxy," continued Oey.
The result shows that the central bar that cuts across the Milky Way's central bulge - made of stars and gas, with a length of 13,000 light-years and with its outer ends rotating at about 150 kilometers per second - could have derailed the stars around it.