One half of the Milky Way is essentially the mirror image of the other, and a whole structure has an uncommon and perfect
symmetry, CFA astronomers say.
Thomas Dame and Patrick Thaddeus of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. discovered a vast
structure at the Milky Way's outskirts, which is most likely the outer extension of the Scutum Centaurus arm from the inner galaxy.
It appears that Scutum-Centaurus wraps all the way around the Milky Way, making it a symmetric counterpart to the
galaxy's other major star-forming arm, Perseus.
The newfound structure lies about 49,000 light-years from the galaxy's center, and one of the arm's many large molecular clouds
contains an amount of molecular hydrogen equivalent to that of 50,000 suns!
The two arms of the Milky Way extend from opposite ends of the galaxy's central, bar-shaped cluster of stars, each winding around the galaxy.
Thomas Dame found the new structure while reviewing galactic data on atomic hydrogen gas, which radiates at a radio wavelength of 21 centimeters.
"I was in the unique position of being able to walk up two flights of stairs to the roof of my building [at Harvard] and search
for carbon monoxide emissions from molecular clouds using the CfA 1.2-meter radio telescope," Dame said.
The structure is located approximately 49,000 light-years from the galaxy's center, and is spanning 60 degrees in the sky.
Every spiral arm in the Milky Way has been found in sections, Thomas Dame comments.
When astronomers realized that the Sagittarius arm (found in the northern sky) and the Carina arm (in the south) were part of a single,
larger structure, they became known as the Sagittarius-Carina arm.
The two scientists belive that the new arm is an extension of Scutum-Centaurus and suggested 'Outer Scutum-Centaurus' as a more logical name."
The structure is longer than the known parts of the Scutum-Centaurus arm but was previously overlooked because it tilts out of
the plane of the galaxy, following the outer galaxy's warp.
"This is a major new discovery," comments Robert Benjamin, of the University
"Most studies that examine spiral arms focus on the galaxy's plane. The team's "identification of the feature as a
discrete structure is new, and the discovery that it contains molecular gas makes a very strong case for this being a spiral arm."
Abnormal Star Discovered In The 'Forbidden Zone'
A team of astrophysicists from Germany, France and Italy have discovered in the constellation Leo is an old star.
The star's existence raised at once many questions for scientists.
The object is definitely not as its "contemporaries" that appeared immediately after the Big Bang event.
Possible Water In The Atmosphere Of A Super-Earth
Four CfA astronomers, Zachory Berta, David Charbonneau, Jean-Michel Desert, and Jonathan Irwin, together with six colleagues,
used the Hubble Space Telescope to probe the atmosphere around the transiting super-Earth known as GJ1214b.
This exoplanet has a mass of 6.5 Earth-masses and a radius of 2.7 Earth-radii, and it orbits a small M-dwarf star (its diameter
is only 21% of the Sun's).
Astronomical Mystery - Tremendous Explosion And Appearance Of Odd Rings
Twenty five years ago, on 1987 February 23, the brightest supernova of modern times was observed in the Large Magellanic Cloud.
The collision occurred at speeds near 60 million kilometers per hour and shock-heats the ring material causing it to glow.
Over time, astronomers have watched and waited for the expanding debris from this tremendous stellar explosion to crash into previously expelled material...
Doesn't Secret Dark Matter Exist?
The more scientists study dark matter they know lesser and are not particularly optimistic about their results.
After completing this study, we know less about dark matter than we did before," said Matt Walker, of the Harvard-Smithsonian Center for Astrophysics.
A mysterious and still unknown substance is totally invisible in the Universe and reveals its presence only through its gravitational pull...
Dwarf Irregular Galaxy That Forces Scientists To Re-Evaluate Old Theory
Astronomers from Center for Astrophysics of the University of Porto, Portugal and Oskar Klein Centre, Stockholm University, Sweden come up
with new findings regarding one of the most studied objects - the dwarf galaxy I Zw 18.
The results led the scientists to the conclusion that this enigmatic blue compact dwarf might force
astronomers to review current galaxy formation models and much of what is known about galaxy formation and evolution might need substantial revision.
Violent Dragon Clash Billions Of Years Ago
NGC 5907 is sometimes called the "Splinter" or Knife Edge Galaxy because of its unusual appearance.
It is a spiral galaxy lying in the Dragon constellation,
about 40 million light-years from Earth that could have been formed through a gigantic collision of galaxies, 8 to 9 billion years ago.