Astronomers find evidence Milky Way grew 'inside out'
CAMBRIDGE, England, Jan. 20 (UPI) -- European astronomers say new evidence suggests the Milky Way may have formed from the inside out, expanding out from the center.
New observations
using a European Southern Observatory telescope in Chile suggests older
stars inside the Solar Circle -- the orbit of our sun around the center
of the Milky Way, which takes roughly 250 million years to complete --
are far more likely to have high levels of magnesium, suggesting this
area contained more stars that "lived fast and died young" in the past.
Tracking
the amount of chemical elements in a star other than hydrogen and
helium -- the two elements comprising most stars -- allows a
determination of how rapidly different parts of the Milky Way were
formed, the astronomers said.
"The different chemical elements of
which stars -- and we -- are made are created at different rates -- some
in massive stars, which live fast and die young, and others in sun-like
stars, with more sedate multibillion-year lifetimes," Gerry Gilmore,
lead investigator on the Gaia-ESO Project, said.
The important
differences in stellar evolution across the Milky Way disc suggest very
efficient and short star formation timescales occurring inside the Solar
Circle whereas, outside the sun's orbit, star formation took much
longer, the researchers said.
"We have been able to shed new light
on the timescale of chemical enrichment across the Milky Way disc,
showing that outer regions of the disc take a much longer time to form,"
study leader Maria Bergemann from Cambridge University's Institute of
Astronomy said. Source :http://goo.gl/Zibv9Y
Dev Pratap is Engineering student ,he is an active blogger and a Space enthusiast, He has Involved in many theoretical research in astronomy and space science,he has served as Volunteer for SETI Home for a period of 5 years in BOINC(Berkley Open Infrastructure for Network Computing).
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