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/ Technology News / 2007 / December 2007 / December 13, 2007 Milky Ways two stellar halos have opposing spins |
Chemical reaction in landslide rocks may start wildfires
A new research has suggested that a chemical reaction in rocks in landslides may be responsible for starting wildfires. ANI
Now, a project to encourage visually-impaired pupils to take up computer science
The U.S. National Science Fioundation (NSF) is funding an initiative at the Rochester Institute of Technology (RIT) that has been designed to help prepare visually impaired middle school and high school students participate in computer science programs at the collegiate level. ANI
New invention to neutralize hurricanes with help from supersonic jet
Scientists have put forward a patent application about developing a supersonic hurricane neutralizer, which can put a spanner in the atmospheric works by flying supersonic jet aircraft in concentric circles around a hurricanes eye, the calm area around which the storm rotates. ANI
We call it home, but the Milky Way can still surprise us. It does not have just one halo of stars, but two.
Washington, Dec.13 : We call it home, but the Milky Way can still surprise us. It does not have just one halo of stars, but two.
According to Daniela Carollo of the Torino Observatory in Italy and her colleagues, the discovery was made while measuring the metal content and motion of 20,000 stars in the Milky Way through the Sloan Digital Sky Survey.
Carollo and her team found that the halo can be divided into two distinct regions, rotating in opposite directions, and containing stars of different chemical composition.
The team found that the inner halo is flattened and extends out to about 4.6 x 1017 kilometres from the galactic centre, rotating at 20 kilometres per second, in the same sense that the Sun travels round the galactic centre.
The outer halo is spherical, stretching out to over 6.0 x 1017 kilometres and spinning in the opposite direction at about 70 kilometres per second.
By examining the spectrum of light emitted by the stars, the team also calculated that the inner-halo stars contain three times more heavy atoms than the outer-halo stars, raising questions about when the two halos formed.
"The two haloes appear to have been formed at different times by different mechanisms," believes Carollo.
"This result throws out all our current models of galaxy formation," Carollo reports in her study published in Wednesday's issue of the journal Nature.
ANI